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2 years ago

−2x+7y=10 minus 3x+7y=2

Mathematics

1 answer:

viva [34]2 years ago

3 0

Answer:

I would multiply the first equation by −4 and the second by 3 and add together the two equatins (in columns): ... Step 2. Prepare the equations. Multiply every term in each equation by a ... Subtract Equation (4) from Equation (3). ... How do you solve the system 5x−10y=15 and 3x−2y=3 by multiplication?

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What is the missing angle measure of 112 68 50

serious [3.7K]

It's 130, any quadrilateral's angles add up to 360 and those numbers add up to 230, 360-230 = 130

5 0

3 years ago

Read 2 more answers

Find the measure of angle x. Round your answer to the nearest hundredth. (please type the numerical answer only) A right triangl

mars1129 [50]

Answer:

22.62

Step-by-step explanation:

Cos=12/13

12/13= 0.9231

Cos^-1(0.9231)=22.62

8 0

3 years ago

We would like to create a confidence interval.

Vlada [557]

Answer:

c.A 90% confidence level and a sample size of 300 subjects.

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 $1-\alpha$ , we have the confidence interval with a margin of error of:

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

In which

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

In this problem

The proportions are the same for all the options, so we are going to write our margins of error as functions of $\sqrt{\pi(1-\pi)}$

a.A 99% confidence level and a sample size of 50 subjects.

$n = 50$

99% confidence interval

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The margin of error is

$M = z\sqrt{\frac{\pi(1-\pi)}{n}} = \frac{2.575}{\sqrt{50}}\sqrt{\pi(1-\pi)} = 0.3642\sqrt{\pi(1-\pi)}$

b.A 90% confidence level and a sample size of 50 subjects.

$n = 50$

90% confidence interval

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

The margin of error is

$M = z\sqrt{\frac{\pi(1-\pi)}{n}} = \frac{1.645}{\sqrt{50}}\sqrt{\pi(1-\pi)} = 0.2623\sqrt{\pi(1-\pi)}$

c.A 90% confidence level and a sample size of 300 subjects.

$n = 300$

90% confidence interval

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

The margin of error is

$M = z\sqrt{\frac{\pi(1-\pi)}{n}} = \frac{1.645}{\sqrt{300}}\sqrt{\pi(1-\pi)} = 0.0950\sqrt{\pi(1-\pi)}$

This produces smallest margin of error.

d.A 99% confidence level and a sample size of 300 subjects.

$n = 300$

99% confidence interval

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The margin of error is

$M = z\sqrt{\frac{\pi(1-\pi)}{n}} = \frac{2.575}{\sqrt{300}}\sqrt{\pi(1-\pi)} = 0.1487\sqrt{\pi(1-\pi)}$

6 0

3 years ago

5. Review: Determine if the data set is a function and explain why or why not: {(-5,6).(-6, 2).(-2,6). (-1,8). (4,6)

Roman55 [17]

Answer:

It is a function

Step-by-step explanation:

Domain: (-5, -6, -2, -1, 4)

Range: (2, 6, 8)

each element of the domain maps to one element of the range, so it is a function.

7 0

3 years ago

Identify the value of a if

Serga [27]

Answer:

a=1/3

Step-by-step explanation:

from the point on the graph

x=4 and y=8

substitute them into the equation:

y=a(x-2) (2x+4)

you will get

8=a(4-2) (2(4)+4)

8=a(2) (8+4)

8=a(2) (12)

8=2a×12

8=24a

divide both sides by 24

8/24=24a/24

1/3=a or a=1/3

7 0

3 years ago