Có 6 quyển sách và 7 quyển vở. Hỏi có bao nhiêu cách chọn
một trong các quyển nói trên?

Answers

Answer 1
I know right!!! SO CRAZY
Answer 2

Answer:

eeeeeee

Step-by-step explanation:

xdddddddudjdjdjdjdjdjsjsjsjsjsjsjsjjsjsjsjsjsjsjsjsjsjsjjs


Related Questions

PLEASE HELP WILL MARK BRAINLIEST.Write the log equation as an exponential equation. You do not need to solve for x.
In (5) = 2x

Answers

Answer:

10x ÷ 5x=2x

10x ÷ 5x = 2x

10x÷ 5x = 2x

Answer:

[tex]e^{2x}=5[/tex]

Step-by-step explanation:

Recall that [tex]\log_b a=c\implies b^c=a[/tex].

In this case, we need to find the base of the logarithm. The logarithm [tex]\ln[/tex] denotes natural [tex]\log[/tex] with a base of [tex]e[/tex], a mathematical constant.

Therefore, we can re-write the equation as:

[tex]\log_e5=2x[/tex]

To write the equation as an exponential equation, recall the definition of log (first sentence of explanation):

[tex]\boxed{e^{2x}=5}[/tex]

A rectangular area is to be enclosed using an existing

wall as one side 100m of fencing are available for the

three side. It is desire to make the areas as large as

possible. Find the necessary dimension of the

enclosure and the maximum area.​

Answers

Answer:

[tex]\text{Dimensions: 25 x 50},\\\text{Area: }1,250\:\mathrm{m^2}[/tex]

Step-by-step explanation:

Let the one of the side lengths of the rectangle be [tex]x[/tex] and the other be [tex]y[/tex].

We can write the following equations, where [tex]x[/tex] will be the side opposite to the wall:

[tex]x+2y=100,\\xy=\text{Area}[/tex]

From the first equation, we can isolate [tex]x=100-2y[/tex] and substitute into the second equation:

[tex](100-2y)y=\text{Area},\\-2y^2+100=\text{Area}[/tex]

Therefore, the parabola [tex]-2y^2+100y[/tex] denotes the area of this rectangular enclosure. The maximum area possible will occur at the vertex of this parabola.

The x-coordinate of the vertex of a parabola in standard form [tex]ax^2+bx+c[/tex] is given by [tex]\frac{-b}{2a}[/tex].

Therefore, the vertex is:

[tex]\frac{-100}{2(-2)}=\frac{100}{4}=25[/tex]

Plug in [tex]x=25[/tex] to the equation to get the y-coordinate:

[tex]-2(25^2)+100(25)=\boxed{1,250}[/tex]

Thus the vertex of the parabola is at [tex](25, 1250)[/tex]. This tells us the following:

The maximum area occurs when one side (y) of the rectangle is equal to 25The maximum area of the enclosure is 1,250 square meters The other dimension, from [tex]x+2y=100[/tex], must be [tex]50[/tex]

And therefore, the desired answers are:

[tex]\text{Dimensions: 25 x 50},\\\text{Area: }1,250\:\mathrm{m^2}[/tex]

Get brainiest if right!!

Answers

Answer:

4 1/8 units

Step-by-step explanation:

I believe this to be so if these points were on a number line. You would add the two points together to get the distance between the two points.

Answer ASAP! Please answer! please answer (NOT HARD)

Answers

Answer:

221

Step-by-step explanation:

5(3)2-4

Answer:

221

Step-by-step explanation:

CNNBC recently reported that the mean annual cost of auto insurance is 1049 dollars. Assume the standard deviation is 275 dollars. You take a simple random sample of 72 auto insurance policies.

Find the probability that a single randomly selected value is less than 962 dollars.
P(X < 962) =


Find the probability that a sample of size
n
=
72
is randomly selected with a mean less than 962 dollars.
P(M < 962) =


Enter your answers as numbers accurate to 4 decimal places.

Answers

Answer:

0.3745 = 37.45% probability that a single randomly selected value is less than 962 dollars.

0.0037 = 0.37% probability that a sample of size 72 is randomly selected with a mean less than 962 dollars.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

CNNBC recently reported that the mean annual cost of auto insurance is 1049 dollars. Assume the standard deviation is 275 dollars.

This means that [tex]\mu = 1049, \sigma = 275[/tex]

Find the probability that a single randomly selected value is less than 962 dollars.

This is the p-value of Z when X = 962. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{962 - 1049}{275}[/tex]

[tex]Z = -0.32[/tex]

[tex]Z = -0.32[/tex] has a p-value of 0.3745

0.3745 = 37.45% probability that a single randomly selected value is less than 962 dollars.

Sample of 72

This means that [tex]n = 72, s = \frac{275}{\sqrt{72}}[/tex]

Probability that the sample mean is les than 962.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{962 - 1049}{\frac{275}{\sqrt{72}}}[/tex]

[tex]Z = -2.68[/tex]

[tex]Z = -2.68[/tex] has a p-value of 0.0037

0.0037 = 0.37% probability that a sample of size 72 is randomly selected with a mean less than 962 dollars.

Solve for x. See the image below!

Answers

Answer:

x = 17

Step-by-step explanation:

in such a constellation (two beams from the same point of origin cut through the same circle) the relative relation between the segments of these beams to the overall length of the beam have to be the same :

7 × (7+x) = 8 × (8+13)

49 + 7x = 8 × 21 = 168

7x = 119

x = 17

Which of the following relations represents a function? (0, 3), (0.-3). (-3,0). (3.0)) (-2. 4). (-1.0), (2.0), (2.6) -1.-1), (0.0), (2, 2), (5, 5]] None of these​

Answers

Answer:

(-1.0) (2.0) is the answer

What is the slope of the linear relationship shown in this table of values?​

Answers

Answer: -2 (b)

Step-by-step explanation:

So the slope of the line is the amount that the line changes as it goes along the x or y axis. Think of it like a ramp- goes up or down, steep or flat.

Take a pair of points like (-4, 11) and (2, -1)

{But you can use other points in the chart too. }

-4 to 2 is a distance of 6 --> that is the x

11 to -1 is a distance of -12 --> that is the y

We want the change in y over (or divided by) change in x.

-12 / 6 = -2

Answer:

B

Step-by-step explanation:

Calculate the slope m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (- 4, 11) and (x₂, y₂ ) = (2, - 1) ← 2 ordered pairs from the table

m = [tex]\frac{-1-11}{2-(-4)}[/tex] = [tex]\frac{-12}{2+4}[/tex] = [tex]\frac{-12}{6}[/tex] = - 2 → B

If ⃗ = + + is perpendicular to both ⃗ = 5 + − 2 and = 3 − 3 + 6 , find and .

Answers

Answer:

The values of [tex]m[/tex] and [tex]n[/tex] are 0 and 2, respectively.

Step-by-step explanation:

If [tex]\vec {c} = m\,\hat{i} + n\,\hat{j} + \hat{k}[/tex] is perpendicular to [tex]\vec {a} = 5\,\hat{i} + \hat{j} -2\,\hat{k}[/tex] and [tex]\vec {b} = 3\,\hat{i} - 3\,\hat{j} + 6\,\hat{k}[/tex], then the following relationships must be observed:

[tex]\vec {c}\,\bullet\,\vec {a} = 0[/tex] (1)

[tex]\vec{c}\,\bullet \,\vec{a} = 0[/tex] (2)

Then, we expand the previous expressions:

[tex](m, n, 1)\,\bullet\,(5, 1, -2) = 0[/tex]

[tex]5\cdot m + n = 2[/tex] (1b)

[tex](m, n, 1)\,\bullet\,(3, -3, 6) = 0[/tex]

[tex]3\cdot m - 3\cdot n = -6[/tex] (2b)

Then, we solve for [tex]m[/tex] and [tex]n[/tex]:

[tex]m = 0, n = 2[/tex]

The values of [tex]m[/tex] and [tex]n[/tex] are 0 and 2, respectively.

Solve for d.
d + 67 = 87
р
Submit

Answers

Answer:

[tex]d=20[/tex]

Step-by-step explanation:

[tex]d+67=87[/tex]

Subtract 67 from both sides

[tex]d=20[/tex]

Hope this is helpful

Answer:

d = 20

Step-by-step explanation:

Which of the following describes the end behavior of the function ƒ(x) = –5x3 + 3x2 + x – 9?

A)

As x → –∞, y → +∞ and as x → +∞, y → –∞

B)

As x → –∞, y → –∞ and as x → +∞, y → +∞

C)

As x → –∞, y → –∞ and as x → +∞, y → –∞

D)

As x → –∞, y → +∞ and as x → +∞, y → +∞

Answers

Answer:

A

Step-by-step explanation:

f(x)=-5x³+3x²+x-9

leading coefficient is negative and it is of odd degree.

so it starts from above onthe left  and ends at the bottom ont he right.

HELP!!! Please simplify: 4^(x+1)*2^(2x)

Answers

Answer:

24x+2

Step-by-step explanation:

The correct answer should be 2^4x+2! i hope this helps!

A shoreline observation post is located on a cliff such that the observer is 280 feet above sea level. The observer spots a ship approaching the shore and the ship is traveling at a constant speed.

Requried:
a. When the observer initially spots the ship, the angle of depression for the observer's vision is 6 degrees. At this point in time, how far is the ship from the shore?
b. After watching the ship for 43 seconds, the angle of depression for the observer's vision is 16 degrees. At this point in time, how far is the ship from the shore?

Answers

Using the slope concept, it is found that the distances from the shore at each moment are given by:

a) 2664 feet.

b) 976 feet.

What is a slope?

The slope is given by the vertical change divided by the horizontal change, and it's also the tangent of the angle of depression.

Item a:

The vertical distance is of 280 feet, with an angle of . The distance from the shore is the horizontal distance of x. Hence:

[tex]\tan{6^\circ} = \frac{280}{x}[/tex]

[tex]x = \frac{280}{\tan{6^\circ}}[/tex]

x = 2664.

Item b:

The vertical distance is of 280 feet, with an angle of 16º. The distance from the shore is the horizontal distance of x. Hence:

[tex]\tan{16^\circ} = \frac{280}{x}[/tex]

[tex]x = \frac{280}{\tan{16^\circ}}[/tex]

x = 976.

More can be learned about the slope concept at https://brainly.com/question/18090623

The diameter of the stem of a wheat plant is an important trait because of its relationship to breakage of the stem. An agronomist measured stem diameter in eight plants of a particular type of wheat. The mean of these data is 2.275 and the standard deviation is 0.238. Construct a 80% confidence interval for the population mean.

Answers

Answer:  

7.79771≤x≤8.20229  

Step-by-step explanation:  

Given the following  

sample size n = 8  

standard deviation s = 0.238  

Sample mean = 2.275  

z-score at 980% = 1.282

Confidence Interval = x ± z×s/√n  

Confidence Interval = 8 ± 1.282×0.238/1.5083)  

Confidence Interval = 8 ± (1.282×0.15779)

Confidence Interval = 8 ±0.20229    

CI = {8-0.20229, 8+0.20229}  

CI = {7.79771, 8.20229}

Hence the required confidence interval is 7.79771≤x≤8.20229

Part B: Find an irrational number that is between 9.5 and 9.7. Explain why it is irrational. Include the decimal approximation of the irrational number to the nearest hundredth. (3 points)

Answers

Answer: Part A: Find a rational number that is between 9.5 and 9.7. Explain why it is rational.

Step-by-step explanation:

Part B: Find an irrational number that is between 9.5 and 9.7. Explain why it is irrational. Include the decimal approximation of the irrational number to the nearest hundredth

When Riley goes bowling, her scores are normally distributed with a mean of 160 and
a standard deviation of 13. Using the empirical rule, determine the interval that
would represent the middle 68% of the scores of all the games that Riley bowls.

Answers

Answer:

The interval that would represent the middle 68% of the scores of all the games that Riley bowls is (147, 173).

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 160, standard deviation of 13.

Middle 68% of the scores of all the games that Riley bowls.

Within 1 standard deviation of the mean, so:

160 - 13 = 147.

160 + 13 = 173.

The interval that would represent the middle 68% of the scores of all the games that Riley bowls is (147, 173).

calculate to the nearest million m³.the current amount of water in the berg river dam​

Answers

Answer:

See Explanation

Step-by-step explanation:

The question is incomplete, as the dimension of the dam is not given.

However, a general way of calculating volume is to calculate the base area and the multiply by height.

Take for instance,the dam has a rectangular base of 20m by 30m.

The base area will be

Area = 20m * 30m = 600m²

If the height of the water in the dam is 40m, then the volume is:

Volume = 600m² * 40m

Volume = 24000m³

NEED HELP FAST!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answers

Answer:

A. f(x) = -0.5(x+3) (x-5)

In triangle ABC, AC = 4, BC = 5, and 1 < AB < 9. Let D, E and F be the
midpoints of BC, CA, and AB, respectively. If AD and BE intersect at G
and point G is on CF, how long is AB?
A. 2
B. 3
C. 4
D. 5

Answers

the answer would be 4
The answer will be C.4

y'+y=y^2; y(0)=-1/3
Giải phương trình trên

Answers

Step-by-step explanation:

[tex]y' + y = y^2[/tex]

We can rewrite the differential equation above as

[tex]\dfrac{dy}{dx} + y = y^2[/tex]

[tex]dy = (y^2 - y)dx[/tex]

or

[tex]\dfrac{dy}{y^2 -y} = dx[/tex]

We can rewrite the left side of the equation above as

[tex]\dfrac{dy}{y^2-y}=\dfrac{dy}{y(y-1)}= \left(\dfrac{1}{y-1} - \dfrac{1}{y} \right)dy[/tex]

We can the easily integrate this as

[tex]\displaystyle \int \left(\dfrac{1}{y-1} - \dfrac{1}{y} \right)dy = \int dx[/tex]

or

[tex]\displaystyle \int \dfrac{dy}{y-1} - \int \dfrac{dy}{y} = \int dx[/tex]

This will then give us

[tex]\ln |y-1| - \ln |y| + \ln |k| = x[/tex]

where k is the constant of integration. Combining the terms on the left hand side, we get

[tex]\ln \left|\dfrac{k(y-1)}{y} \right| = x[/tex]

or

[tex]\dfrac{y-1}{y} = \frac{1}{k}e^x[/tex]

Solving for y, we get

[tex]y= \dfrac{1}{1- \frac{1}{k} e^x}=\dfrac{k}{k-e^x}[/tex]

We know that [tex]y(0)= \frac{1}{3}[/tex], so when we substitute [tex]x=0[/tex], we find that [tex]k = -\frac{1}{2}[/tex].

Therefore, the final form of the solution to the differential equation above is

[tex]y = \dfrac{1}{1+2e^x}[/tex]

Statins are used to keep cholesterol in check and are a top-selling drug in the U.S. The equation:

S

1.3
x
=
6


gives the amount of sales (
S
) of statin in billions of dollars
x
years after 1998. According to this equation, how much will/did people in the U.S. spend on statins in the year 2008?

Answers

Answer:

19 billion dollars

Step-by-step explanation:

Given the equation :

S - 1.3x = 6

Where, S = amount of sale of statin in billions of dollars ; x = number of years after 1998

Amount spend in 2008

x = 2008 - 1998 = 10

Put x = 10 in the equation ;

S - 1.3x = 6

S - 1.3(10) = 6

S - 13 = 6

S = 6 + 13

S = 19

People will spend about 19 billion dollars on statin in 2008


A national survey of 1516 respondents reached on land lines and cell phones found that the percentage of adults who favor legalized abortion has dropped from 55% a year ago to 45%. The study claimed that the error
atributable to sampling is 4 percentage points. Would you claim that a majority of people are not in favor of legalized abortion?

Answers

Answer:

The upper bound of the interval is below 0.5, which means that it can be claimed that a majority of people are not in favor of legalized abortion

Step-by-step explanation:

Confidence interval:

Sample proportion plus/minus margin of error.

In this question:

Sample proportion of 0.45, margin of error of 0.04. So

0.45 - 0.04 = 0.41

0.45 + 0.04 = 0.49

The confidence interval is of (0.41,0.49). The upper bound of the interval is below 0.5, which means that it can be claimed that a majority of people are not in favor of legalized abortion

A country's population in 1993 was 204 million. In 2000 it was 208 million. Estimate the population in 2015 using the exponential growth formula. Round your answer to the nearest million. P- Aekt​

Answers

Answer:

217

Step-by-step explanation:

y=6x/5 +27 find y-intercept and slope

Answers

Answer:

General equation of a line is given by y = mx +c, where m is the gradient /slope, c is the intercept. To find for the intercept on y- axis, put x = 0.[tex]y = \frac{6(0)}{5 } + 27 \\ y = \frac{0}{5} + 27 \\ y = 27 \\ therefore \: the \: intercept \: on \: y \: is \: 27 \\ [/tex]By comparison, [tex]y = mx + \: c \\ y = \frac{6}{5} x \: +27 \\ m = \frac{6}{5 \: } \: \\ hence \: slope \: is \: \frac{6}{5} [/tex]


Determine the relationship between the two triangles and whether or not they can be proven to be congruent.

Answers

Answer:

The relationship between the above two triangles is SAS and they are congruent

Which expression has the same value as the one below?
38 + (-18)
O A. 38
O B. 38 - 18
O C. 38 + 18
O D. 56

Answers

Answer:

answer is B 38-18

Step-by-step explanation:

38 + (-18)

38-18

I believe the answer is B

38+ (-18) turns into 38-18 because after removing the parentheses around -18 there is no need for the +

Two cars are parked at the points (4, 5) and (8, 7). Find the midpoint between the two cars. O (12, 12) O (-6, -6) O (6,6) O (-2,-1) < Previous 00:00 / 00:00​

Answers

Answer:

(6,6)

You can use the midpoint formula.

need an answer show work please thank you

Answers

Answer:

[tex]\text{C. }1[/tex]

Step-by-step explanation:

In the question, we're given that the notation [tex]\#\#(a,b,c)[/tex] produces a number [tex]a[/tex] less than the product of [tex]b[/tex] and [tex]c[/tex] raised to the [tex]a[/tex] power. Let the number produced be [tex]n[/tex]. As a mathematical equation, we can write this production as [tex]n=(bc)^a-a[/tex]

For [tex]\#\#(2, 5, x)[/tex], we can assign:

[tex]a\implies 2[/tex] [tex]b\implies 5[/tex] [tex]c\implies x[/tex]

Substituting these values into [tex]n=(bc)^a-a[/tex], we get:

[tex]23=(5x)^2-2[/tex]

Add 2 to both sides:

[tex]25=(5x)^2[/tex]

Take the square root of both sides:

[tex]5=|5x|[/tex]

For [tex]y=|z|[/tex], there are two cases:

[tex]\begin{cases}y=z,\\y=-z\end{cases}[/tex]

Therefore, we have:

[tex]\begin{cases}5=5x, x=\boxed{1}\\5=-(5x), 5=-5x, x=\boxed{-1}}\end{cases}[/tex]

The only answer choice applicable is [tex]\boxed{\text{C. }1}[/tex].

Identify the restrictions on the domain.

x+1x+9÷xx−4

x≠−1,4

x≠−9,4

x≠−1,0

x≠−9,0
[tex]Identify the restrictions on the domain. x+1x+9÷xx−4x≠−1,4x≠−9,4x≠−1,0x≠−9,0[/tex]

Answers

1,0 9,0 hope I helped

What is the radius of a circular swimming pool with a diameter of 20 feet?

Answers

Answer:

10 feet

Step-by-step explanation:

The half of 20 is 10. So, hence it is 10 feet.

The radius of a circular swimming pool with a diameter of 20 feet will be 10 feet.

What is a circle?

It is the close curve of an equidistant point drawn from the center. The radius of a circle is the distance between the center and the circumference.

Assume 'r' is the radius of the circle and 'd' is the diameter of the circle.

The radius of the circle is half of the diameter of the circle. Then the equation is given as,

r = d / 2

The diameter of the swimming pool is 20 feet. Then the radius of the swimming pool is given as,

r = 20 / 2

r = 10 feet

The radius of a roundabout pool with a measurement of 20 feet will be 10 feet.

More about the circle link is given below.

https://brainly.com/question/11833983

#SPJ2

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