Expand and simplify 2(x+7)+3(x+1)

What is the value of x in the equation −6 + x = −5? 1, 11, −1, −11

goldfiish [28.3K]

Answer:

1 exactly iam genius

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4 0

1 year ago

Find the value of x that will make A||B A- 2x + 50 5x - 80 B- x = [?]

LenKa [72]

Answer:

15

Step-by-step explanation:

If A||B then the sum of given angles must be equal to 180°

2x + 5 + 5x - 80 = 180 add like terms

7x - 75 = 180 subtract 75 from both sides

7x = 105 divide both sides by 7

x = 15

8 0

3 years ago

Read 2 more answers

20(20-x)=300 what is x

neonofarm [45]

Answer:

x = 5

Step-by-step explanation:

20(20-x)=300

1. Divide both sides by 20.

20(20-x)/20 = 300/20

2. Simplify.

20-x=15

3. Subtract 20 from both sides.

20-x-29=15-20

4. Simplify.

-x=-5

5. Divide both sides by -1.

-x/-1 = -5/-1

6. Simplify.

x=5

5 0

2 years ago

At 95% confidence, how large a sample should be taken to obtain a margin of error of 0.03 for the estimation of a population pro

Gnom [1K]

Answer:

A sample of 1068 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:

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

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

At 95% confidence, how large a sample should be taken to obtain a margin of error of 0.03 for the estimation of a population proportion?

We need a sample of n.

n is found when M = 0.03.

We have no prior estimate of $\pi$ , so we use the worst case scenario, which is $\pi = 0.5$

Then

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

$0.03 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.03\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.03}$

$(\sqrt{n})^{2} = (\frac{1.96*0.5}{0.03})^{2}$

$n = 1067.11$

Rounding up

A sample of 1068 is needed.

8 0

2 years ago

Which of the following applies the law of cosines correctly and could be solved to find m∠E? ANSWERS: A) cos E = 312 + 392 – 2(3

defon

This question is incomplete because the options were not properly written.

Complete Question

Which of the following applies the law of cosines correctly and could be solved to find m∠E? ANSWERS:

A) cos E = 31²+ 39² – 2(31)(39)

C) 56² = 39² – 2(39) ⋅ cos E

D) 56² = 31² + 39² – 2(31)(39) ⋅ cos E

Answer:

D) 56² = 31² + 39² – 2(31)(39) ⋅ cos E

Step-by-step explanation:

From the above diagram, we see are told to apply the law of cosines to solve for m∠E i.e Angle E

The formula for the Law of Cosines is given as:

c² = a² + b² − 2ab cos(C)

Because we have sides d , e and f and we are the look for m∠E the law of cosines would be:

e² = d² + f² - 2df cos (E)

e = 56

d = 39

f = 31

56² = 39² + 31² - (2 × 39 × 31) × cos E

Therefore, from the above calculation and step by step calculation, the option that applies the law of cosines correctly and could be solved to find m∠E

Is option D: 56² = 31² + 39² – 2(31)(39) ⋅ cos E

8 0

3 years ago