Please tell me please

Answer:

It will take 15.029 years for element X to reach mass of 260 grams

Step-by-step explanation:

The half life period of radioactive element X is 26 years

The initial mass of radioactive element X is 260 grams

Elapsed time = half life * log (beginning amount /ending amount)/log 2

Substituting the given values, we get

Elapsed time = 26 * log (390/260)/log 2

=  15.209 years

Answer:

$28.35

Step-by-step explanation:

[tex]45\% \times 63 \\ = 0.45 \times 63 \\ = 28.35[/tex]

Answer:

Step-by-step explanation:

Answer:

10 hours (I am not positive)

Step-by-step explanation:

We first want to find the volume of pool which is 30 x 18 x 4 = 2160.

Then you are going to divide by 216 to find how many hours it takes to drain the whole pool. (I'm not that big of an expert)

Answer:

Step-by-step explanation:

The secret trick to factoring is the greatest common factor.

The greatest common factor of 9 and 21 is 3. Thus, our expression is

3(3 + 7).

The greatest common factor of 14 and 28 is 7. Our expression is

7(2 + 4)

The greatest common factor of 80 and 56 is 8. This makes our expression

8(10 + 7).

This is a 30-60-90 right triangle.

In this special triangle, opposite 60 degrees = sqrt{3}. Thus, x = sqrt{3}.

Answer:

1/12

Step-by-step explanation:

He has a 1/4 pan left and wants to divide that into 3 equal pieces. So in night he will eat 1/3 of what he has left from the 1/4 pan. To figure out how much one slice is from an entire pan:

1/4 * 1/3  = 1/12

Answer:

15

Step-by-step explanation:

This is simply just 5 x 3 = 15

Answer:

Mean x¯¯¯ 5.8888888888889

Median x˜ 6

Mode 7

Range 3

Minimum 4

Maximum 7

Count n 9

Sum 53

Quartiles Quartiles:

Q1 --> 5

Q2 --> 6

Q3 --> 7

Interquartile

Range IQR 2

hope i helped:) can u plz mark me brainlest

Answer:

the mean is 5.88888888889

Step-by-step explanation:

to find the mean, add all the data results together and divide by how many results you have.  

for example:  5+4+5+7+7+7+5+7+6= 53

53 divided by 9= 5.88888888889

have a good day

Answer:

Inequality Form:

x<4

1<4

3<4

-1004<4

Interval Notation:

(−∞,4)

(-1004,4)

(3,4)

(1,4)

Step-by-step explanation:

Answer:

Step-by-step explanation:

The aim of this question is to see if we can infer and conclude that vitamin C has a good impact in preventing colds based on the evidence provided.

Null hypothesis: Vitamin C has no effect on preventing colds.

Alternative hypothesis: Vitamin C has a strong effect on preventing colds.

Assuming, significance level = 0.05

Since the p-value for the difference is 0.03 which is less than 0.05.

Hence, the null hypothesis is rejected (which is there is no effect of vitamin C).

As a result, it can be concluded that Vitamin C has a major impact on the prevention of colds.

Answer:

x=16, y=-4

Step-by-step explanation:

-1(x-y=12)

x+7y=-20

-x+y=-12

x+7y=-20

8y=-32

y=-4

x-4=12

x=16

Answer:

x= 8, y= -4

Step-by-step explanation:

You can subtract one equation by another to eliminate x

(x-y)-(x+7y)=12-(-20)

-8y = 32

y= -4

Substitute y =  -4 in the first equation:

x-(-4) = 12

x =8

Answer:

D) 5,572

Step-by-step explanation:

4/3×pi×r^3

4/3×3.14×11^3

5572.453...

5572

Answer:

15,840 feet

Step-by-step explanation:

5,280*3 = 15840

Since she runs 3 miles each morning, and 1 mile is 5,280,

then you multiply 5,280*3

Answer:

25π or 78.5mm²

Step-by-step explanation:

[tex]A=3.14*5^{2} \\ =3.14*25\\ =78.5[/tex]

Answer:

Step-by-step explanation:

The formula for the area of a circle is

A = π*r²

Now we can rewrite with the radius. *Note* I am using 3.14 for pi to make it easier*

A = π*5²

Solve

5² = 25

25 * 3.14 = 78.5

Now since the measurements were done in millimeters, we will add mm to the end.

Also since it is area, we need to add ²

78.5 mm²

9514 1404 393

Answer:

  (x1, x2) = (3, -4)

Step-by-step explanation:

As with any 2-step linear equation, subtract the constant, then multiply by the inverse of the coefficient of the variable.

  [tex]\left[\begin{array}{cc}3&2\\5&5\end{array}\right]\left[\begin{array}{c}x\\y\end{array}\right]+\left[\begin{array}{c}1\\2\end{array}\right]=\left[\begin{array}{c}2\\-3\end{array}\right]\\\\\left[\begin{array}{cc}3&2\\5&5\end{array}\right]\left[\begin{array}{c}x\\y\end{array}\right]=\left[\begin{array}{c}1\\-5\end{array}\right]\\\\\left[\begin{array}{c}x\\y\end{array}\right]=\dfrac{1}{5}\left[\begin{array}{cc}5&-2\\-5&3\end{array}\right]\left[\begin{array}{c}1\\-5\end{array}\right][/tex]

Performing the multiplication of the matrix by the vector gives the solution.

  x = ((5)(1) +(-2)(-5))/5 = 15/5 = 3

  y = ((-5)(1) +(3)(-5))/5 = -20/5 = -4

Using your variables, x1, x2, the solution is ...

  (x1, x2) = (3, -4)

Answer:

The pvalue of the test is 0.0784 > 0.01, which means that at this significance level, we do not reject the null hypothesis that the percentage of blue candies is equal to 29%.

Step-by-step explanation:

The candy company claims that the percentage of blue candies is equal to 29%.

This means that the null hypothesis is:

[tex]H_{0}: p = 0.29[/tex]

We want to test the hypothesis that this is true, so the alternate hypothesis is:

[tex]H_{a}: p \neq 0.29[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.29 is tested at the null hypothesis:

This means that [tex]\mu = 0.29, \sigma = \sqrt{0.29*0.71}[/tex]

Suppose that in a random selection of 100 colored candies, 21% of them are blue.

This means that [tex]n = 100, X = 0.21[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.21 - 0.29}{\frac{\sqrt{0.29*0.71}}{\sqrt{100}}}[/tex]

[tex]z = -1.76[/tex]

Pvalue of the test:

The pvalue of the test is the probability of the sample proportion differing at least 0.21 - 0.29 = 0.08 from the population proportion, which is 2 multiplied by the pvalue of Z = -1.76.

Looking at the z-table, z = -1.76 has a pvalue of 0.0392

2*0.0392 = 0.0784

The pvalue of the test is 0.0784 > 0.01, which means that at this significance level, we do not reject the null hypothesis that the percentage of blue candies is equal to 29%.

Answer:

No solutions

Step-by-step explanation:

-8x+2y = -16

   4x-y  = 10 [multiply by 2 so it is easier to add/subtract]

-8x+2y = -16

8x -2y = 20

        0 = 4

0 and 4 cant be equal so theres no solution

Answer:

122

Step-by-step explanation:

122 + 58 = 180

Answer:

x=122°

Step-by-step explanation:

58° and x form a straight angle, which is 180°.

x+58°=180°

x=180°-58°=122°

Answer:

2/7

Step-by-step explanation:

when you divide a fraction by a fraction, flip the second fraction. 1/3 x 6/7 is 6/21, then you reduce it. divide 6 by 3 and 21 by 3, =2/7

Answer:

0.28571428571

Step-by-step explanation:

This is the calculated answer.

But after a lot of. technical,work the answer,ends up be 2/7

Answer:

108

Step-by-step explanation:

Answer:

3x^2+6x-2

Step-by-step explanation:

(5x2 + 4x + 3) - (2x2 - 2x + 5)

5x^2+4x+3-2x^2+2x-5

3x^2+6x-2

Answer:

(x - 2) (x^2 + 3)

Step-by-step explanation:

x^3-2x^2+3x-6

Factor by grouping

Answer:

Factor by grouping

Step-by-step explanation:

[tex]x^{3}-2x^{2} +3x-6[/tex]

[tex]x^{2} (x-2) + 3 (x-2)[/tex]

[tex](x^{2} +3)(x-2)[/tex]

Answer:

it is likely because the majority of the outcomes are in your favor

Answer:

A

Step-by-step explanation:

Impossible, did it on usatestprep

Answer:

24 units

Step-by-step explanation:

Each line plot equals 2, so the length is 8 and the hight is 4. 8+8+4+4 = 16 + 8 = 24 units.

Answer:

good

Step-by-step explanation:

So when you do the (,) things the x-axis  would go first for example

say the x-axis=5 and the y-axis= 9 it would be (5,9)

hope this helps plz mark brainlest

Answer: see work

Step-by-step explanation:

Blue:

9-5+3x4

Red:

10+6/3+8x2

Answer:

Work

Step-by-step explanation:

Blue:

9-5+6-5

Red:

4+4+5

Answer:

-5 cos (2x)

Step-by-step explanation:

Reflection over x axis just means "multiply by -1" so the answer is

f(x) = 5 cos (2x)

g(x) = -5 cos (2x)

Answer:

If you think numbers with fractions are annoying, consider transforming the number into fractions!

Step-by-step explanation:

7 1/2 is (14+1)/2, and 3 1/8 is (24+1)/3. Not you have 15/2 miles for 25/3 days and by dividing them you get 0.9 miles a day