All categories

1 year ago

If x + y = 2 and x - y = 6, solve for x and y.

Mathematics

1 answer:

anyanavicka [17]1 year ago

7 0

Answer:

Step-by-step explanation:

Givens

x + y = 2

x - y = 6

Solution

Just add the two equations together. The y's will drop out.

x + y = 2

<u>x - y = 6 </u> Add

2x = 8 Divide by 2

2x/2 = 8/2 Combine

x = 4 Substitute x = 4 into the top equation

x + y = 2

4 + y = 2 Subtract 4 from both sides

4-4+y=2-4 Combine

y = - 2

Answer

x = 4

y = -2

You might be interested in

How large a sample should be selected to provide a 95% confidence interval with a margin of error of 6? Assume that the populati

marshall27 [118]

Using the z-distribution, it is found that a sample of 171 should be selected.

<h3>What is a z-distribution confidence interval?</h3>

The confidence interval is:

$\overline{x} \pm z\frac{\sigma}{\sqrt{n}}$

The margin of error is:

$M = z\frac{\sigma}{\sqrt{n}}$

In which:

$\overline{x}$ is the sample mean.

z is the critical value.

n is the sample size.

$\sigma$ is the standard deviation for the population.

For this problem, the parameters are:

$z = 1.96, \sigma = 40, M = 6$

Hence we solve for n to find the needed sample size.

$M = z\frac{\sigma}{\sqrt{n}}$

$6 = 1.96\frac{40}{\sqrt{n}}$

$6\sqrt{n} = 40 \times 1.96$

$\sqrt{n} = \frac{40 \times 1.96}{6}$

$(\sqrt{n})^2 = \left(\frac{40 \times 1.96}{6}\right)^2$

n = 170.7.

Rounding up, a sample of 171 should be selected.

More can be learned about the z-distribution at brainly.com/question/25890103

#SPJ1

4 0

1 year ago

What is the reasonable estimate for -3/2 x -5 1/4

Lady bird [3.3K]

Answer:

7.875......7.9.....or 8

Step-by-step explanation:

-3÷2×-21÷4= 7.875

63÷8=7.875

3 0

3 years ago

Read 2 more answers

Explain what mistake was made in the problem below and what should be the

romanna [79]

Answer:

Instead of moving the 3x to the opposite side of the equation they moved the 2x. And the correct answer is x=-6 not x=6.

Step-by-step explanation:

Student Work:

2(x + 4) – 8 = 3x+10-4

2x + 8–8 = 3x + 6

2x = 3x + 6

- 3x – 3x

X = 6

My work:

2(x+4)-8=3x+10-4

2x+8-8=3x+6

2x=3x+6

-x=6

x=-6

7 0

3 years ago

The number 2400 is first increased by 30%.The value obtained is next decreased by 20%.Find the final number

kvasek [131]

<em>2400 is increased by 30%.</em>

so,

2400 + (30/100 * 2400)

2400 + (30 * 24)

2400 + 720

3120

<em>this number is decreased by 20%.</em>

so,

3120 - (20/100 * 3120)

3120 - (2 * 312)

3120 - 624

2496

therefore, the final number will be 2496.

3 0

3 years ago

please help me find these answers! Ill give brainliest and 5 stars ill make sure to thank you! just please help im suffering ove

Damm [24]

Answer:

4: 3 1/4 inches

5: 13 inches

Step-by-step explanation:

4 0

2 years ago