Mr. johnson bought 22 cupcakes and 30 drinks for his class. ms. richards bought 30 cupcakes and 35 drinks for her class. mr. johnson spent $44.40 and ms. richards spent $53.75.
how much does a cupcake cost?
$
how much does a drink cost?
$

Cupcakes =c
Drinks = d
22 c + 30d = $44.40...eqn 1
30c + 35d = $53.75...eqn 2
Multiply eqn 1 by 7 and eqn 2 by 6
154c +210d =$310.80...eqn 3
180c+ 210d = $322.5...eqn 4
Eqn 4 - eqn 3
26 c = $11.70
C = 11.7/26 = 45c
Subst c = 45c in eqn 1
$9.90 + 30d =$44.40
d = ($44.40-$9.90)/30 = $1.15