Jim wants to buy some cupcakes. If he buys 4 cupcakes, he will have $5 left. If he buys 10 cupcakes, he will need $4 more. How much does Jim have?
Call the price of one cupcake, P
So
4P + 5 = 10P - 4 rearrange as
10P - 4P = 4 + 5
6P = 9
P = 9/6 = $1.50 = the cost of one cupcake
His total money = 4(1.50) + 5 = $11
