Cakes = x
Cupcakes = y
On Saturday, 6x + y = $165
We are told x = 12, so 6(12) + 3y = 165
72 + 3y = 165
Subtract the entire equation by 72:
3y = 93
Divide by 3 to simplify:
y = 31 cupcakes sold
9.3m questions
12.0m answers