Explanation:
Since Castel sold 6 apple pies and 4 lemon meringue pies for $80, we have 6x + 4y = $80.
Also Gabriella sold 6 apple pies and 5 lemon meringue pies for $94, we have 6x + 5y = $94.
6x + 5y = $94
- (6x + 4y = $80)
=> y = $14.
Therefore 6x + 5($14) = $94, 6x = $24, x = $4.
Hence each apple pie costs $4 and each lemon meringue pie costs $14.