Given the equations y=x+7 and y=x^2+4 how many times do they intercept?

Answers

Answer 1

According to the following graph, the equations  y=x+7 and y=x²+4 will intercept 2 times at the points (-1.3, 5.7) and (2.3, 9.3).

Intercept:

The point where the line or curve crosses the axis of the graph is known as intercept.

That is, if a point crosses the x-axis, then it is known as the x-intercept. Similarly, if a point crosses the y-axis, then it is called as the y-intercept.

Given,

Here we have the equation  y=x+7 and y=x²+4.

Now, we need to find the number of times the equation is intercepts.

First, we have to plot the graph for the given equations,

Then based on that one we have easily identify the intercepting points in order to get the results.

In the following graph, the blue line represents the equation y=x²+4 and the red line represents the equation y = x + 7.

While we looking into the graph we have identified that the two lines are intersecting at two point they are (-1.3, 5.7) and (2.3, 9.3).

To know more about Intercept here.

https://brainly.com/question/14180189

#SPJ1

Given The Equations Y=x+7 And Y=x^2+4 How Many Times Do They Intercept?

Related Questions

sound travels at a rate of about 1.1*10^3 feet per second. Suppose a mining company detonates a bundle of dynamite at a distance of 625 feet from a canyon wall. At the time of a detonation the miners sit safely at a distance of 2,600 feet from the dynamite. How long after detonation will the miners hear the echo of the blast off the canyon wall? Round to the nearest tenth if necessary.

Answers

what in your opinion is the moral in the story ?

this is a pre for something later on in the future please help me i will give brainliest and dont make it sound to smart or use big words becausee i dont type like that

Answers

Using the Pythagorean Theorem, it is found that:

The length of the bar is of c = 8.73 ft.The amount of netting needed is of 132.76 ft².

Pythagorean Theorem

The Pythagorean Theorem is a geometry axion relates the length of the sides [tex]l_1[/tex] and [tex]l_2[/tex], which are the separated by the angle of 90º, of a right triangle with the length of the hypotenuse h, stating that the hypotenuse squared is the sum of the legs squared, according to the following equation:

[tex]h^2 = l_1^2 + l_2^2[/tex]

For the netting, it is found that:

The legs are of 8 ft and 3.5 ft.The hypotenuse is of c.

Hence the measure c, representing the length of the bar, is calculated as follows:

c² = 8² + 3.5²

c = sqrt(8² + 3.5²)

c = 8.73 ft.

The amount of netting needed is the area of the entire goal, composed by:

A rectangle of dimensions 12 ft and 8.73 ft.Two right triangles of dimensions 8 ft and 3.5 ft.

Hence:

A = 12 x 8.73 + 2 x 1/2 x 8 x 3.5 = 132.76 ft².

More can be learned about the Pythagorean Theorem at https://brainly.com/question/343682

#SPJ1

tony buys 6 packages of cookies. each package of cookies cost $2.50. how much will he spend ​

Answers

Answer:

Tony will spend 15$.

Step-by-step explanation:

2.50 * 6= 15($)

34=−2x34 I don’t understand
this problem

Answers

You can try reversing it 34 x -2 =34 or if it’s a true or false question it will be false. Hope this helps.

Kamryn’s doctor recommended that she drink 64 fluid ounces of water every day. There are about 30 milliliters in 1 fluid ounce. Which measurement represents the number of milliliters in 64 fluid ounces?

HELP PLEASE DUE IN 10 MINS

Answers

64 fluid ounces contain 1920 milliliters.

64 oz of liquid is what?

Oz to Half Gallon Conversions

A half gallon is equal to 64 ounces in a gallon measurement.

OZ or ML: Which is bigger?

A milliliter is equal to how many ounces. The conversion factor from fluid ounces to milliliter is 1 fluid ounce = 30 milliliter.

64 ounces is equal to how many glasses of water?

This equates to eight 8-ounce glasses or 2,000 ml (approximately 64 ounces) for a person who consumes 2,000 calories per day.

Given: She regularly drinks 64 fluid ounces of water.

       1 fluid = 30 milliliters

       => 30 × 64 = 1920 milliliters

To know more about 64 oz of liquid visit:-
https://brainly.com/question/439009

#SPJ13

Can you please help me out with a question

Answers

[tex]P(\text{Event)}=\frac{n\text{ (Event)}}{Total\text{ Event}}[/tex][tex]P(\text{outer most ring)=}\frac{area\text{ of the outer most ring}}{area\text{ of the dartboard}}[/tex][tex]\begin{gathered} Area\text{ of the dartboard=}\pi\times R^2 \\ Where\text{ R=6} \\ \text{Area of the dartboard=}\pi\times6^2 \\ \text{Area of the dartboard=}36\pi \end{gathered}[/tex][tex]\begin{gathered} \text{Area of the outermost ring=Area of the dartboard - Area of the inner ring} \\ \text{Area of the outermost ring=36}\pi-(\pi\times4^2)=36\pi-16\pi=20\pi \end{gathered}[/tex][tex]\begin{gathered} P(\text{outermost ring)=}\frac{20\pi}{36\pi} \\ P(\text{outermost ring)=}\frac{5}{9} \end{gathered}[/tex]

The probability of the outermost ring is 55.6%

-4/0 divided by 5 11/14

Answers

Answer: undefined

Step-by-step explanation:

3(x+1) +4 = 2x -2 + x

Answers

Answer:

No solution.

Step-by-step explanation:

3(x+1)+4=2x-2+x

-> distribute

3x+3+4=2x-2+x

-> simplify (add constants & x terms)

3x+7=3x-2

-> variable cancels out

7=-2

-> this is not true

Untrue statement; no solution.

Put empty parenthesis/brackets: [,] / (,) or simply put "no solution."

The diagram shows a driveway to be paved. The Lincoln family needs to determine the amount of Hot Asphalt Mix to purchase in order to pave their new driveway, which will have a 6-inch base (thickness). The density of Hot Asphalt Mix depends on mix proportions and types of material used. Assuming a density of 145 pounds per cubic foot, how many tons of asphalt will the Lincoln family need to purchase?

Answers

Answer:

bbbbbbbbbbbbbbbb

kjajs

Which ordered pairs represent points on the graph of this equation? Select all that apply. x= – 1 /2 y

Answers

The ordered pairs that represent points on the graph of the equation 3x + 2y = -12. is; point (-4,0)

What is the ordered pair on the graph?

An equation of the line is defined as the linear equation that has a degree of one. The equation of the line contains two variables x and y. Thus, the third parameter will be the slope of the line which represents the elevation of the line.

The general form of the equation of the line is y = mx + c

where;

m is the slope

c is the y-intercept

We will find the ordered pair that satisfies the equation with each pair of points as;

3(-6) + 2(7) = -4

3(-4) + 2(0) = -12 YES

3(0) + 2(7) = 14

3(3) + 3(-3) = 0

3(6) + 2(0) = 18

The only ordered pair that satisfies the given linear equation is (-4, 0)

Read more about ordered pairs at; https://brainly.com/question/1528681

#SPJ1

Complete question is;

Which ordered pairs represent points on the graph of this equation? Select all that apply.

3x + 2y = -12

(-6, 7)

(7, 6)

(-4,0)

(0,7)

(3,-3)

(6,0)

A trail mix recipe calls for 3 cups of pecans for 15 packets. At this rate how many cups of pecans will he need for 90 packets?

Answers

Answer:

Step-by-step explanation:

3 cups for 15 packets would be 5 packets for each cup. So 1 cup is 5 packets of trail mix. Which means 5×90= 45

The answer is 45.

some students decide to take a bike ride. for the first two hours they travel at a speed of 15 mi/hr, they then stop for lunch for an hour. the students then ride for another hour at 10 mi/hr. what was their average speed for the trip?

Answers

10 miles per hour is the average journey speed.

Given that,

Some pupils choose to ride bikes. They move at a 15 mph average speed for the first two hours, and then they stop for lunch for an hour. The pupils ride at a 10 mph speed for an additional hour.

Average speed is ( total distance ) / ( total time )

During the 1st 2 hrs:

distance = speed * time

distance = 15 *2 = 30 miles

During the last hour:

distance = speed * time

distance = 10 *1 = 10 miles

Average speed = 30+10 / 2+1+1 = 40/4 = 10 mil/hr

Therefore, their average speed for the trip is 10 mil/hr

To learn more about speed click here:

https://brainly.com/question/7359669

#SPJ4

The sum of an integer and 2 times the next consecutive integer is -22. Find the value of the lesser integer

Answers

Answer: gurl you think i know

Step-by-step explanation:

Question 3 (10 points)

Answers

Answer:

11

Explanation:

if you want to find the answer to a question like this just put the square root symbol on to your calculator before you type the number it wants you to get an answer for and the correct answer will appear

hope this helps:)

Answer:

11

Step-by-step explanation:

[tex]\sqrt{121} = \sqrt{11^{2} } = 11[/tex]

Find the y-intercept and the slope of the line. 3x+4y=-7

Answers

Answer: m(slope) = -3/4, b(y-int) = -7/4

Answer:

The slope is -3/4 and the y intercept is 74.

Step-by-step explanation:

I just know I had this question.

a particular fruit's weights are normally distributed, with a mean of 717 grams and a standard deviation of 18 grams. if you pick 12 fruits at random, then 16% of the time, their mean weight will be greater than how many grams? give your answer to the nearest gram.

Answers

If the mean is 7171 grams, the standard deviation is 18 grams and 12 fruits are selected at random. Then, the mean weight will be 734.901 grams greater.

Let X be the random variable of the fruit's weight.

We have, the mean and standard deviation as 717 grams and 18 grams respectively.

We want to find the specific gram value for which 16% of the fruits are heavier, i.e. the 84th percentile of X's normal distribution

Now, Solving for x:

P( X < x ) = Normal( 717, 18 ), Z = 0.84

So,

P( [X - 717] / 18 < [x - 717] / 18 ) = P( Z < [x - 717]/18 ) = 0.84, where Z is a standard normal random variable

Now,

Standard Normal CDF( [x - 717]/18 ) = 0.84

Then, from the standard normal table: [x - 717]/18 = Inverse Standard Normal CDF( 0.84 ) = 0.9945

Therefore,

[ x - 717 ] / 18 = 0.9945

Multiplying 18 on each side of the equation,

x - 717 = 0.9945 × 18

x - 717 = 17.901

Adding 717 on each side of the equation,

x - 717 + 717 = 17.901 + 717

x = 734.901

Learn more about standard deviation here:

brainly.com/question/475676

#SPJ4

What is the end behavior of the graph of the polynomial function f(x) = -x5 + 9x4 - 18x³?
O As x→-co, Y→→co and as x→co, y →-00
As x→-co, Y→→∞ and as x→co, y →∞
ය.
O As x→-co, Y→co and as x→co, y →→∞0
O As x→-co, y →co and as x→co, y → co

Answers

The option (A) x → -∞, f(x) → ∞ and x → ∞, f(x) → -∞ if the polynomial function is  f(x) = -x⁵ + 9x⁴ - 18x³.

What is a function?

It is defined as a special type of relationship, and they have a predefined domain and range according to the function every value in the domain is related to exactly one value in the range.

It is given that:

The polynomial function is:

f(x) = -x⁵ + 9x⁴ - 18x³

After plotting the graph of the polynomial function:

From the graph;

x → -∞, f(x) → ∞

x → ∞, f(x) → -∞

Thus, the option (A) x → -∞, f(x) → ∞ and x → ∞, f(x) → -∞ if the polynomial function is  f(x) = -x⁵ + 9x⁴ - 18x³.

Learn more about the function here:

brainly.com/question/5245372

#SPJ1

Combine like​ terms, if possible. Write the result with descending powers. -7x^4 + 4x^4 - 6x^4

Select the correct choice below and fill in the answer box to complete your choice.

A. The polynomial can be simplified. -7x^4 + 4x^4 - 6x^4 =

B. The polynomial cannot be simplified. The polynomial written in descending powers is =

Answers

The polynomial can be reduced to -9x^4

Addition of Polynomial

To solve this, we can simply add the similar polynomials or polynomials with the same power. This will help us simplify the polynomial to the lowest possible value.

[tex]-7x^4 + 4x^4 -6x^4 = -9x^4[/tex]

The polynomial given is simplified to become -9x^4

Learn more on addition of polynomials here;

https://brainly.com/question/17517586

#SPJ1


Bette used 3 jumbo cans of frosting to frost 105
cupcakes for the cupcake challenge at her school
and 5 jumbo cans of frosting to frost an
additional 175 cupcakes. How many jumbo cans
of frosting would she need to frost 280
cupcakes?

Answers

The number of jumbo cans of frosting would she need to frost 280 cupcakes is 8.

Given that, Bette used 3 jumbo cans of frosting to frost 105 cupcakes and 5 jumbo cans of frosting to frost an additional 175 cupcakes.

What are proportions?

Proportion is a mathematical comparison between two numbers.  According to proportion, if two sets of given numbers are increasing or decreasing in the same ratio, then the ratios are said to be directly proportional to each other.

Let number of jumbo cans of frosting would she need to frost 280 cupcakes be x.

Now the proportion is

3/105 = 5/175 = x/280

⇒ 5/175 = x/280

⇒ 175x = 280 × 5

⇒ x = 1400/175

⇒ x = 8

Therefore, the number of jumbo cans of frosting would she need to frost 280 cupcakes is 8.

To learn more about the proportions visit:

https://brainly.com/question/7096655.

#SPJ1

Which equation could possibly represent the graphed function?
A polynomial function graph where the solid line intersects X-axis on (minus 4,0), (minus 2,0) and (4,0). The same line intersects Y-axis at (minus 30, 0) and (2, minus 48)

A. f(x) = (x − 4)(x + 2)(x + 4)
B. f(x) = (x − 4)2(x − 2)
C. f(x) = (x + 4)2(x + 2)
D. f(x) = (x − 4)(x − 2)(x + 4)

Answers

Answer:

answer is A

as the graph cuts the x axis at 4 which is shown by (x-4). and cut by -2 and -4 which is shown by (x+2) and (x+4).

The answer is A
Hope it is correct?!?!

The formula C=3.14d can be used to approximate the circumference of a circle given its diameter. Company A manufactures and sells a certain washer with an outside circumference of 4 centimeters. The company has decided that a washer whose actual circumference is in the interval 3.9≤C≤4.1 centimeters is acceptable. Use a compound inequality and find the corresponding interval for diameters of these washers.

Answers

1.242 ≤ d ≤ 1.305 is the corresponding interval for the diameter of the washer.

Given that,

Company A makes and sells a washer having a 4-centimeter outer radius. The corporation has decided on a washer with an actual radius in the range of 3.9 ≤ C ≤ 4.1.

Inequality is defined as the connection of an equation having the symbol ( ≤, ≥, <, >) in place of the assignment operator.

Here,

C = 3.14d

Given inequality,

3.9 ≤ C ≤ 4.1

3.9 ≤ 3.14d ≤ 4.1

dividing both sides of the inequality by 3.14,

1.242 ≤ d ≤ 1.305

As a result, the needed matching spacing for the washer's diameter is 1.242 ≤ d ≤ 1.305.

Learn more about intervals at

https://brainly.com/question/28382224?referrer=searchResults

#SPJ9

Six more than the quotient of a number and 9 equals 4

Answers

Answer: x= -18

Step-by-step explanation:

Your equation would be (x/9)+6=4

Subtract 6 by both sides.

Multiply 9 by both sides.

Then you should get -18.

ben is making a dessert that requires 212 lb of strawberries and 112 lb of blueberries. strawberries cost $1 less per pound than blueberries. ben spent a total of $9.50 on the fruit. what is the price per pound of each type of fruit?

Answers

Answer:

Step-by-step explanation:Price per pound of strawberries is $-0.31635 and blueberries is $0.6836.

Explanation :

Given data ;

Weight of strawberries required for dessert = 212 lb

Weight of blueberries required for dessert = 112 lb

Total cost spent = $9.50

Let,

Cost of blueberries per pound =x

Cost of strawberries per pound = (x-1)

We know that,

Cost of blueberries for overall weight + Cost of strawberries for overall weight = Total cost spent on fruits.

x(112) + (x-1)212 = 9.50

112x + 212x – 212 = 9.50

324x = 221.5

X = 221.5/324

X = $0.6836

So, (x-1) = $-0.31635

To learn more about pound click here :

https://brainly.com/question/23268373

#1234

Price per pound of strawberries is $0.02476 and the price per pound of blueberries is $0.03794

Given that ;

Ben is making a dessert that requires 212 lbs of strawberries and 112 lbs of blueberries. Strawberries cost $1 less per pound than blueberries. Ben spent a total of $9.50 on the fruit.

So according to the question get the price per pound of each type of fruit;

Let ' x ' be the price per pound of strawberries and ' y ' be the price per pound of blueberries.

By assuming the following equations;

212x - 112y = 1 → ( I )

212x + 112y = 9.5 → ( II )

By solving above equations ( I ) ( II ) we get;

424x = 10.5

      x = 10.5/424

      x = 0.02476

224y = 8.5

      y = 8.5/224

      y = 0.03794

Price per pound of strawberries is $0.02476 and the price per pound of blueberries is $0.03794

To learn more about Pound click here:

brainly.com/question/27994061

#SPJ4

10 is 25% of what number?

Answers

Answer:

10% of 25 is 5/2 or 2½ as a fraction and 2.5 as a decimal. Let's find 10% of 25.

Step-by-step explanation:

 

30+29+14 Joshua rewrote the expression as 39+14+29 what property did Joshua used to rewrite the expression

Answers

Commutative property of addition.

This property states that changing the order of numbers while adding or multiplying them does not change the final answer.

A manufacturer determines the cost of making a computer component is $3.232323 write the repeating decimal cost as a fraction and as a mixed number

Answers

Answer:

$320/99$3 23/99

Step-by-step explanation:

You want the repeating decimal cost ...

  [tex]\$3.\overline{23}[/tex]

written as a fraction and as a mixed number.

Fraction

One can convert the repeating decimal to a fraction by multiplying it by a power of 10 equal to the number of repeating digits.

This cost number (C) has 2 repeating digits (23), so we want to multiply it by 10^2:

  [tex]100C=10^2\times3.23\overline{23}=323.\overline{23}[/tex]

Now, we can subtract the original cost to cancel the repeating decimal fraction:

  [tex]100C -C = 323.\overline{23}-3.\overline{23}=320[/tex]

Dividing by the coefficient of C, we have the fraction we want:

  [tex]C=\boxed{\dfrac{320}{99}}[/tex]

Mixed number

This is expressed as a mixed number by figuring the quotient and remainder.

  [tex]\dfrac{320}{99}=\boxed{3\dfrac{23}{99}}[/tex]

A company that manufactures bicycles has a fixed cost of $90,000. It costs $200 to produce each bicycle. The total cost for the company is the sum of its fixed cost and variable costs Write the total cost, C, as a
function of the number of bicycles produced, x Then, find and interpret C(100)
The total cost function is C(x)=

Answers

Answer:

Total cost: C(x) = 90,000 + 200x in dollars

C(100) = $110,000

This means that the total cost for the company when it produces 100 bikes would be $110,000

Step-by-step explanation:

First, you have a fixed cost, so you would start by setting C(x) to that:

C(x) = 90,000

Then, you have a cost of $200 PER bike that is made. The amount of bikes is represented by x. So you will have to multiply cost per bike by how many bikes are manufactured:

200x

Add this variable cost to the function underlined above.

C(x) = 90,000 + 200x

This is your function C(x).

Now for C(100), PLUG IN 100 for x:

C(100) = 90,000 + 200(100)

Multiply out:

C(100) = 90,000 + 20000

Then add these together to get the value:

C(100) = 110,000

This is the amount of money it would cost to make 110000 bikes, as interpreted above.

what is the first quartile of this data set?
11,12,15,16,17,19,22,24,29,33,38

Answers

The first quartile of the given data set would be 15 which is The middle of the numbers from the beginning up.

What is the first quartile of the data set?

When data points are organized in ascending order, the first quartile, or lower quartile, (Q1), is the value at which 25% of them are located.

The given data set is:

11,12,15,16,17,19,22,24,29,33,38

Since the number of elements in the data set is 11. As a result, the data are divided into two equal parts by the sixth term. The median of the data is 19.

The middle of the numbers from the beginning up to and including the first middle value: 11,12,15,16,17.

The middle value is 15.

Therefore, the first quartile of this data set would be 15.

Learn more about the first quartile here:

brainly.com/question/9707857

#SPJ1

What is an equation of the line that passes through the points (-2, 5) and (−2,−8)?

Answers

The equation of the line that passes through (-2, 5) and (−2,−8) is: x = -2.

What of the Equation of a Line?

The equation of a line that passes two given points on the line, can be expressed in slope-intercept form as y = mx + b. In this form, the variable "m" represents the slope of the line, while the "b" represents the y-intercept.

Find the slope using the two points  (-2, 5) and (−2,−8):

Slope (m) = change in y / change in x = (-8 - 5)/(-2 -(-2))

Slope (m) = -13/0 [cannot divide]

The slope of the line is undefined. This means the line is a vertical line that intercepts the x-axis at -2.

The equation of the vertical line would therefore be: x = -2.

Learn more about equation of a line on:

https://brainly.com/question/13763238

#SPJ1

graph the equation, y=x/3-4

Answers

Step-by-step explanation:

With the equation

y

=

|

x

+

3

|

4

, we know that the term inside the absolute value mark will never be less than zero, which means the smallest

y

can be is

y

=

4

. This value is achieved with

|

x

+

3

|

=

0

, putting

x

=

3

. So that is our first point,

(

3

,

4

)

.

We're dealing with

x

terms (versus

x

2

or

x

or any other form of

x

), so the graph coming off

(

3

,

4

)

will be lines. Since there the coefficient of the

x

term is 1, the slope of those lines will be 1 and

1

(with the x term inside the absolute value, we look at both

±

1

).

The standard graph for an absolute value graph is for it to be in the shape of a V. And so we can expect our graph to have points

(

4

,

3

)

and

(

2

,

3

)

- and we can plug in those values to prove it:

y

=

|

x

+

3

|

4

3

=

|

4

+

3

|

4

3

=

|

1

|

4

3

=

1

4

3

=

3

and

3

=

|

2

+

3

|

4

3

=

|

1

|

4

3

=

1

4

3

=

3

The graph itself will look like this:

graph{abs(-x+3)-4 [-10, 10, -5, 5]}

Other Questions
Barbara has 25 shirts in her closet 0.6 of her shirts have short sleeves. How many shirts with long sleeves does Barbara have in her closet? What formed a channel on mars? Question 3 of 10What did Henry David Thoreau believe people had a moral duty to do to lawsthat were unjust to a group of people?OA. HonorOB. DisobeyO C. QuestionOD. Change the impact of the recession of 2009 has seen slow recovery which lasted well into 2013. if an individual saves $5,700 and elects to place the total dollar ammount into a savings account earing 2.75 apr compounded monthly, how much will thr original deposit grow in 12 yearsd P4-7) the following object is dimensioned incorrectly. identify the incorrect dimensions and list all mistakes associated with them. then, dimension the object correctly using proper dimensioning techniques. there are six mistakes. If earths axis were not tilted at all, in other words, if it were perpendicular to the earths plane of orbit, what effects would that have on people living in the United States? Answer the questions below. Find the missing angle. which receptor is most sensitive to 300 hz vibrations? question 19 options: meissner's corpuscle hair follicle receptor pacinian corpuscle merkel cell-neurite complex ruffini ending A rectangular auditorium seats 1749 people the number of seats in each row exceed the number of rows by 20 find the number of seats in each row on july 1, 2025, bramble co. pays $13,920 to oriole insurance co. for a 1-year insurance contract. both companies have fiscal years ending december 31. abu is creating a virtual machine template to enable rapid server deployment at his organization. he creates a virtual machine named vm1. on vm1, he installs windows server 2019 and names the server serverx. next, he installs server roles and features and adds third-party software. he then runs the system preparation tool. alice and bill are at the top of a cliff of height h. both throw a ball with initial speed v0, alice straight down and bill straight up. the speeds of the balls when they hit the ground are va and vb. if there is no air resistance, which is true? who brought south dakota vs dole to the supreme court? putanginamokagiapakyu Describe the pattern of precipitation in this place. Is it seasonal or year-round? Taking a position on the French Revolution was difficult for Washington because:A. the legislative branch was charged with overseeing diplomacy.B. his cabinet was in favor of the revolution, but he was entirely against it.C. he had personal ties to the French that he did not want to break.D. the presidents role in foreign policy had not yet been specifically defined. HELPPPPPPPPP PLEASEEEEEEEEEE the smithsonian institution exists to preserve historical and cultural items of value and to share those items with the public; it does not exist to maximize the wealth of any shareholders. this entity is organized as a(n) group of answer choices Answer the following given the arithmetic sequence -55, -47, -39, -31.Write the general term (aka the rule) for the nth term of this sequence. (Simplify [Distribute and Combine] the arithmetic sequence formula).f(n) =15th term =