Katie went shopping with her friends Erin. Katie bought 3 shirts and 2 pairs of pants for $80. Erin bought 3 shirts and 4 pairs of pants for $116. How much did one shirt cost? How much did one pair of pants cost?

Step-by-step explanation:

shirt = x, pants: y

Katie equation: 3x + 2y = 80, Erin equation: 3x + 4y = 116

3x + 2y = 80

3x = 80 - 2y

x = 80/3 - 2y/3

3 (80/3 - 2y/3) + 4y = 116

80 - 2y + 4y = 116

80 + 2y + 116

2y = 36

y = 18, pants cost $18

3x + 4 (18) = 116

3x + 72 = 116

3x = 44

x = 14.66 ... (66 is repeating), shirts cost $14.66

check work:

Katie: 3 (14.66) + 2 (18) = 79.98 which is roughly 80.