All categories

3 years ago

Solve the following system : -x + 5y = 8 and 3x + 7y = -2

Mathematics

1 answer:

poizon [28]3 years ago

4 0

-x + 5y = 8

multiply this equation by 3

-3x + 15y = 24

now add it to the other equation ( elimination)

-3x + 15y = 24

3x + 7y = -2

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

0x + 22 y = 22

divide each side by 22

y =1

substitute into -x + 5y =8 to find x

-x + 5(1) = 8

-x + 5 = 8

-x =3

divide by -1

x =-3

Answer (-3,1)

Choice A

You might be interested in

Write the product in its simplest form c^7×(-3c)

sveticcg [70]

Answer:

-3c^8

Step-by-step explanation:

3 0

2 years ago

Apply the distributive property to create an equivalent expression. (1-2g+4h)x5

kifflom [539]

Answer: 5-10g+20h

Step-by-step explanation:

You can rewrite as 5(1-2g+4h). 5x1 equals 5, 5x2g=10g, 5x4h=20h, then you get 5-10g+20h

-viridiancat4, an 8th grader! :)

8 0

2 years ago

Help me please solve the circled question show your work

Rasek [7]

Part 1) Use the fact that there are 12 inches in a foot

a) How many inches tall is a 7 foot basketball player?

we know that

1 foot=12 inches

so by proportion

$\frac{12}{1} \frac{inches}{foot} =\frac{x}{7} \frac{inches}{feet} \\ \\x=12*7\\ \\x=84\ inches$

therefore

the answer Part 1a) is

$84\ inches$

Part b) If a yard is a 3 feet long, how many inches are in a yard?

we know that

1 yard=3 feet

1 foot=12 inches

Convert 3 feet to inches

by proportion

$\frac{12}{1} \frac{inches}{foot} =\frac{x}{3} \frac{inches}{feet} \\ \\x=12*3\\ \\x=36\ inches$

therefore

the answer Part 1b) is

$36\ inches$

Part 2) At the farmer's market two pounds of peaches cost $4.20 How much will five pounds cost?

by proportion

$\frac{4.20}{2} \frac{\$}{pounds} =\frac{x}{5} \frac{\$}{pounds} \\ \\2*x=4.2*5\\ \\x=4.2*5/2=\$10.5$

therefore

the answer Part 2) is

$\$10.5$

Part 3) Janice mother gave her a ten dollars bill to buy five pounds each of bananas and apples at the grocery store. When she got there she found that bananas were 80 c per pound and apples were $1.40 per pound.

Did Janice's mother give her enough money? If so, should she receive any change? If not, how much more money does she need?

we know that

Find the cost of the bananas

$5\ pounds*0.80\frac{\$}{pounds}=\$4$

Find the cost of the apples

$5\ pounds*1.40\frac{\$}{pounds}=\$7$

Sum the cost of the bananas and the cost of the apples

$\$4+\$7=\$11$

$\$11 > \$10$ ------> Janice's mother didn't give her enough money

She needs more money

She needs-------> $\$11-\$10=\$1$

therefore

the answer part 3) is

She needs $\$1$ more

3 0

2 years ago

How to put 17/4 into a mixed number

KiRa [710]

Divide the top by bottom. So 17 divided by 4. Which would be around 4.25

4 0

2 years ago

Read 2 more answers

A fair spinner has 9 equal sections: 2 red, 3 blue and 4 green.

elixir [45]

Probability of 2 consecutive greens equals 4/9*3/8=1/6
Probability of not getting equals 1-1/6=5/6

4 0

2 years ago