Question

Jeff bought 4 oranges and 7 apples for a total of $4.88. Gene bought 12 oranges and 8 apples for a total of $7.88. What is the cost of each orange and each apple?

Answer 1

4x+7y=4.88 -> mult by -3 -> -12x-21y=-14.64
12x+8y=7.88
-12x-21y=-14.64
Add the two above equations together, the y will be left:
-13y=-6.76
y=0.52 —> cost of each apple (plug back into one of original equations, I chose 4x+7y=4.88:
4x+7(0.52)=4.88
Solve for x.
x=0.31 —> cost of each orange