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3 years ago

Solving the following system using the elimination of substitution method. 5a+3b=11 -2a+3=b

Mathematics

1 answer:

PSYCHO15rus [73]3 years ago

4 0

Answer:

a = -2

b = 7

Step-by-step explanation:

5a+3b=11

-2a+3=b

substitute for b:

5a + 3(-2a + 3) = 11

5a -6a + 9 = 11

-a = 2

a = -2

b = 7

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According to the synthetic division below, which of the following statements

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Answer:

A, C, and F

Step-by-step explanation:

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2 years ago

Pat has more than twice as much money as Billy, "b". Pat has $50, how much does Billy have?

s344n2d4d5 [400]

$10 because you divide 50 by 5 and you get 10

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2 years ago

One hundred rats with mothers that were exposed to high levels of tobacco smoke during pregnancy were put through a simple maze.

Paul [167]

Answer:

The 90% confidence interval for pis (0.7342, 0.8658).

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 $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

100 rats mothers, 80 went right. So $n = 100, \pi = \frac{80}{100} = 0.8$

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 $Z = 1.645$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.8 - 1.645\sqrt{\frac{0.8*0.2}{100}} = 0.7342$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.8 + 1.645\sqrt{\frac{0.8*0.2}{100}} = 0.8658$

The 90% confidence interval for pis (0.7342, 0.8658).

3 0

2 years ago

A stadium has 50,000 seats. Seats sell for $25 in section A, $20 in section B, and $15 in section C. The number of seats in sect

Novay_Z [31]

Answers:

section A = 25,000 seats

section B = 14,200 seats

section C = 10,800 seats

Your teacher may want you to leave out the commas from each number.

=============================================================

Work Shown:

A = number of seats in section A
B = number of seats in section B
C = number of seats in section C

A = B+C

A+B+C = 50,000

B+C+B+C = 50,000

2(B+C) = 50,000

B+C = 50,000/2

B+C = 25,000

C = 25,000 - B

25A + 20B + 15C = 1,071,000

25(B+C) + 20B + 15C = 1,071,000

25(25,000) + 20B + 15(25,000 - B) = 1,071,000

625,000 + 20B + 375,000 - 15B = 1,071,000

1,000,000 + 5B = 1,071,000

5B = 1,071,000 - 1,000,000

5B = 71,000

B = (71,000)/5

B = 14,200 is the number of seats in section B

C = 25,000 - B

C = 25,000 - 14,200

C = 10,800 is the number of seats in section C

A = B+C

A = 14,200 + 10,800

A = 25,000 is the number of seats in section A

--------------

Check:

A+B+C = 25,000+14,200+10,800 = 50,000

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2 years ago

Four more than three times a number is thirteen. What is this number?

Ostrovityanka [42]

Answer:

Step-by-step explanation:

13-4=9

9/3=3

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2 years ago

Read 2 more answers