SOLUTION: casey and bella are selling pies for a school funraiser. Customers can buy apple pies and lemon meringue paies. Casey sold 6 apple pies and 4 lemon meringue pies for a total of $80

It can be solved in different ways.


You can write the system of equations

    6a + 4L = 80     (1)

    6a + 5L = 94     (2)


and solve it, as the formal Algebra teaches you.


Alternatively, you can notice that the difference between two sets that they sold 
is 1 (one) lemon pie, from one side, and 94-80 = 14 dollars, from the other side.


So, one lemon pie costs $14, and one apple pie costs (from equation (1))


    a =  =  = 4 dollars.


ANSWER.  Apple pie costs $4.  Lemon pie costs $14.