Question

At the fair, jill bought 2 hamburgers and 4 milkshakes for $9.00. jack bought 3 hamburgers and 3 milkshakes and it cost him $10.50. how much does a hamburger cost? how much does a milkshake cost?

Answer 1

x = hamburger cost
y = milkshake cost

Jill: 2x + 4y = 9
Jack: 3x + 3y = 10.5 → y = 3.5 -x

2x + 4(3.5 - x) = 9
2x + 14 - 4x = 9
-2x +14 = 9
-2x = -5
x = 2.5

y = 3.5 - (2.5)
y = 1

A hamburger costs $2.50 and a milkshake costs $1. Hope this helps!