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3 years ago

Write the equation of a line that passes through the point (-2, 1) and has a slope of 4.

Mathematics

1 answer:

stiv31 [10]3 years ago

3 0

Answer:

y=4x-3

Step-by-step explanation:

y=(slope)x+b

y=4x+b

Insert Point:

$1=4(1)+b$

$b=-3$

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Given g(x)=-3x-3g(x)=−3x−3, solve for xx when g(x)=0g(x)=0.

USPshnik [31]

x = - 1

we require to solve - 3x - 3 = 0

add 3 to both sides

- 3x = 3

divide both sides by - 3

x = $\frac{3}{-3}$ = - 1

7 0

3 years ago

In 2008 Alice bought a house. In 2014 she sold it for a 20% profit. In 2019 it was then sold at a 5% loss for £182,400 Work out

Wittaler [7]

Answer:

£160,000

Step-by-step explanation:

Alice bought the house in 2008 for £x.

In 2014, the house sold for a 20% profit, so it sold for 1.2x. (* see explanation below)

In 2019, the house sold for a 5% loss, so it sold for 0.95(1.2x). (* see explanation below)

In 2019, it sold for £182,400.

0.95(1.2x) = 182,400

1.14x = 182,400

x = 182,400/1.14

x = 160,000

Answer: £160,000

* Explanation of 1.2 and 0.95.

A quick way to apply a percent increase or decrease to a number is to using the following method. The number you start with is 100% of the number. If you are adding a percent to it, then add the percent to 100% and convert it to a decimal. If you are subtracting the percent, then subtract the percent from 100% and convert to a decimal. Then multiply the decimal by the original number to find the increased or decreased number.

Example of percent increase:

A book used to cost £10. The price went up by 12%. What is the new price?

100% + 12% = 112% = 1.12

1.12 * £10 = £11.20

Example of percent decrease:

A pair of trousers costs £60. It is on sale at 35% off the regular price. What is the sale price?

100% - 35% = 65% = 0.65

0.65 * £60 = £39

5 0

3 years ago

The state education commission wants to estimate the fraction of tenth grade students that have reading skills at or below the e

Korolek [52]

Answer:

A sample of 499 is needed.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is given by:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

In this question, we have that:

$\pi = 0.21$

90% confidence level

So $\alpha = 0.1$ , z is the value of Z that has a pvalue of $1 - \frac{0.1}{2} = 0.95$ , so $Z = 1.645$ .

How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 90% confidence level with an error of at most 0.03

We need a sample of n, which is found when $M = 0.03$ . So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.03 = 1.645\sqrt{\frac{0.21*0.79}{n}}$

$0.03\sqrt{n} = 1.645\sqrt{0.21*0.79}$

$\sqrt{n} = \frac{1.645\sqrt{0.21*0.79}}{0.03}$

$(\sqrt{n})^2 = (\frac{1.645\sqrt{0.21*0.79}}{0.03})^2$

$n = 498.81$

Rounding up

A sample of 499 is needed.

8 0

3 years ago

Which situation has a unit rate of $7?

cupoosta [38]

Answer:

C is the answer.

Step-by-step explanation:

4 0

3 years ago

Please answer this it’s very hard for me

Nimfa-mama [501]

Answer:

C, D, E, F

Step-by-step explanation:

Remember y=mxb?

m is slope and b is y-intercept

so y=2/7x-9

Remember that slope is RISE/RUN so for every 2 squares that you go up, you go 7 squares to the right.

Also remember that since your graph is going thru your Cartiesian Plane in quadrent 4, your y value in your ordered pairs will most probably be a negative.

Please see the image to help you viualize this.

3 0

3 years ago