Question

Andrea is buying some new shirts and sweaters. She is able to buy 3 shirts and 2 sweaters for $120, or she is able to buy 2 shirts and 4 sweaters for $160. How many dollars does a shirt cost? How many dollars does a sweater cost?

Answer 1

Shirt = $20
Sweater = 30

Explanation:

3sh + 2sw = 120

2sh + 4sw = 160

Multiply (3sh + 2sw = 120) by -2
-6sh + -4sw = -240 -> -6sh -4sw = -240
Add the two equations -6sh -4sw = -240 and 2sh + 4sw = 160 together. -4sh = -80
Shirt = 20
Substitude in 20
3 x 20 = 60 120 - 60 = 60 60/2=30