Question

At the movie theater the blaine family spent $22.00 for twoadult tickets and three child tickets. the hooper family spent $18.50 for one adult ticket and four child tickets. how much did the hu family spend for three adult tickets and one child ticket?

Answer 1

2a+3c=22.00 ......equation 1
a+4c=18.50  =>2a+8c=37.00 .....equation 2
subtract equation one from equation two: 
5c=37-22=15
c=3
a+4*3=18.50 =>a=6.50

for the Hu family: 3*6.50+1*3.00=22.50 dollars