I need help solving this problem on linear systems

Question

You bought 15 one-gallon bottles of apple juice and organge juice for a school dance. The apple juice was on sale for $1.20 per gallon bottle. The orange juice was $2 per gallon bottle. You spent $26. Write algebraic models for the situation. 

Answer 1

A+O = 15

1.2A + 2(O) = 26

1.2A +1.2(O) = 15(1.2) = 18

.8(O) = 8

O = 8/.8 = 10 Orange Juice gallons

A= 15-10 = 5 Apple Juice gallons

1.2(5) + 2(10) = 6+20 = 26