Question

The cost of four sweaters an two pairs of jeans is 140$. The cost of two sweaters an three pairs of jeans is $150.

PART A: Define the variables and write a system of equation to represent this situation.


Part B: Solve the system of euation and find the cost of each of them. Which method did you use to solve? Show your work and label your answer ❤

Answer 1

sweater cost $20 and jeans cost $30

Answer 2

A pair of jeans cost 40 dollars

A sweater costs 15 dollars

Explanation:

Let s = cost a of sweater

j = cost of a pair of jeans

4s +2j = 140

2s +3j = 150

I will use elimination to solve. Multiply the second equation by -2

-2(2s +3j )= 150*-2

-4s -6j = -300

Add this equation to the first equation

-4s -6j = -300

4s +2j = 140

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

-4j = -160

Divide by -4

-4j/-4 = -160/-4

j = 40

A pair of jeans cost 40 dollars

Now we need to find the cost of the sweater

2s +3j = 150

2s +3(40) = 150

2s+120 = 150

Subtract 120 from each side

2s +120-120=150-120

2s = 30

Divide by 2

2s/2=30/2

s = 15

A sweater costs 15 dollars