Question

Gabriel needs to purchase AT LEAST 30 party decorations. The Party Palace charges $0.50 per decorative streamer and $0.25 per balloon, including tax. Which combination of streamers and balloons can Gabriel purchase with $12.50 at the Party Palace?

Answer 1

x = $0.50
y = $0.25

0.5x + 0.25y = 12.5
x + y = 30
x = 30 - y

0.5(30-y) + 0.25y = 12.5
15 - 0.5y + 0.25y = 12.5
0.25y = 15 - 12.5
0.25y = 2.5
y = 10 (ballons)

x = 30 - 10
x = 20 (streamers)