Question 224839
1.20*30+1.40x=1.28(30+x)
36+1.40x=38.4+1.28x
1.40x-1.28x=38.4-36
.12x=2.4
x=2.4/.12
x=20 gal. of 1.40 gas is used.
Proof:
1.20*30+1.40*20=1.28(30+20)
36+28=1.28*50
64=64