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3 years ago

What is 50 − 7k when k = −10

Mathematics

1 answer:

sertanlavr [38]3 years ago

4 0

Answer:

120

Step-by-step explanation:

Substitute the given number for k into the expression:

50 – 7(–10)

Multiply:

50 – (–70)

Simplify:

50 + 70

Solve:

120

Hope this helps! :)

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PLEASE HELP MEEE WILL GIVE BRAINLIEST!!!!

just olya [345]

Part A)

Given

Slope m = 6

Point (7, 2)

Using the point-slope form of the line equation

$y-y_1=m\left(x-x_1\right)$

where

m is the slope of the line

(x₁, y₁) is the point

In our case:

m = 6

(x₁, y₁) = (7, 2)

substituting the values m = 6 and the point (x₁, y₁) = (7, 2) in the point-slope form of the line equation

$y-y_1=m\left(x-x_1\right)$

$y - 2 = 6(x-7)$

Therefore, the equation in point-slope form for the line having the slope m = 6 and containing the points (7,2) will be:

$y - 2 = 6(x-7)$

Part B)

Given

Slope m = -3

Point (3, 8)

Using the point-slope form of the line equation

$y-y_1=m\left(x-x_1\right)$

where

m is the slope of the line

(x₁, y₁) is the point

In our case:

m = -3

(x₁, y₁) = (3, 8)

substituting the values m = -3 and the point (x₁, y₁) = (3, 8) in the point-slope form of the line equation

$y-y_1=m\left(x-x_1\right)$

$y - 8 = -3(x-3)$

Therefore, the equation in point-slope form for the line having the slope m = -3 and containing the points (3, 8) will be:

$y - 8 = -3(x-3)$

3 0

3 years ago

Tess earned $52 for 4 hours of shoveling snow and $71.50 for 5.5 hours of shoveling snow. How long would she have to shovel snow

Deffense [45]

52/4 = 13
$13 = 1 hour.
$6.50 = halfhour

13 x 3 = $39
She would have to work for 3 hours to earn $39

6 0

3 years ago

Read 2 more answers

Convert 510° from degrees to radians

vitfil [10]

Answer:

$\frac{17\pi }{6}$

Step-by-step explanation:

To convert from degrees to radians

radian = degree measure $\frac{\pi }{180}$

= 510 × $\frac{\pi }{180}$

= $\frac{51\pi }{18}$

= $\frac{17\pi }{6}$ radians

6 0

3 years ago

Read 2 more answers

A gardener is planting two types of trees:

Scrat [10]

It will take 4 years for these trees to be the same height

Step-by-step explanation:

A gardener is planting two types of trees:

Type A is 6 feet tall and grows at a rate of 12 inches per year

Type B is 2 feet tall and grows at a rate of 24 inches per year

We need to find exactly how many years it will take for these trees to be the same height

Assume that it will take x years for these trees to be the same height

Type A:

∵ The initial height of the tree is 6 feet

∵ 1 foot = 12 inches

∴ 6 feet = 6 × 12 = 72 inches

∴ The initial height of the tree is 72 inches

∵ It grows at a rate of 12 inches per year

∵ The number of years is x

∴ The height of the tree in x years = 72 + 12 x

Type B:

∵ The initial height of the tree is 2 feet

∴ 2 feet = 2 × 12 = 24 inches

∴ The initial height of the tree is 24 inches

∵ It grows at a rate of 24 inches per year

∵ The number of years is x

∴ The height of the tree in x years = 24 + 24 x

Equate The heights of the two types

∴ 72 + 12 x = 24 + 24 x

- Subtract 2 from both sides

∴ 48 + 12 x = 24 x

- Subtract 12 x from both sides

∴ 48 = 12 x

- Divide both sides by 12

∴ x = 4

It will take 4 years for these trees to be the same height

Learn more:

You can learn more about the word problems in brainly.com/question/10557938

#LearnwithBrainly

3 0

3 years ago

The U.S. Center for Disease Control reports that the mean life expectancy was 47.6 years for whites born in 1900 and 33.0 years

inn [45]

Answer:

b. The null and alternative hypothesis are:

$H_0: \mu_1-\mu_2=0\\\\H_a:\mu_1-\mu_2\neq 0$

c. Student's t distribution, as it is a two-sample test for the difference between means.

d. Test statistic t = 5.42.

P-value = 0

e. They appear to be significantly different, as the sample data gives strong evidence that the difference is greater than 0.

Step-by-step explanation:

This is a hypothesis test for the difference between populations means.

The claim is that the mean life spans in the county is significantly different for whites and nonwhites.

Then, the null and alternative hypothesis are:

$H_0: \mu_1-\mu_2=0\\\\H_a:\mu_1-\mu_2\neq 0$

The significance level is 0.05.

The sample 1 (white), of size n1=124 has a mean of 45.3 and a standard deviation of 12.7.

The sample 2 (non-white), of size n2=82 has a mean of 34.1 and a standard deviation of 15.6.

The difference between sample means is Md=11.2.

$M_d=M_1-M_2=45.3-34.1=11.2$

The estimated standard error of the difference between means is computed using the formula:

$s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{12.7^2}{124}+\dfrac{15.6^2}{82}}\\\\\\s_{M_d}=\sqrt{1.301+2.968}=\sqrt{4.269}=2.066$

Then, we can calculate the t-statistic as:

$t=\dfrac{M_d-(\mu_1-\mu_2)}{s_{M_d}}=\dfrac{11.2-0}{2.066}=\dfrac{11.2}{2.066}=5.42$

The degrees of freedom for this test are:

df=n_1+n_2-2=124+82-2=204

This test is a two-tailed test, with 204 degrees of freedom and t=5.42, so the P-value for this test is calculated as (using a t-table):

$\text{P-value}=2\cdot P(t>5.42)=0.0000002$

As the P-value (0.0000002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the mean life spans in the county is significantly different for whites and nonwhites.

4 0

3 years ago