How much did they sell??

Question

At the game, the Junior class sold slices of pizza for $.75 each and hamburgers for $1.35 each. They sold 40 more slices of pizza than hamburgers and their sales totaled $292.50. How many slices of pizza did they sell?

Answer 1

^_x 

Answer 2

We can assume that:

x is the slices of pizza they sold, y is the amount of hamburgers they sold.

so, x - y = 40 

     .75x + 1.35y = 292.50

From the first equation, we can get: y = x - 40

    Then plug in (x-40) for y in the second equation: .75x + 1.35(x - 40) = 292.50

      .75x + 1.35x - 54 = 292.50

      2.1x - 54 = 292.50

      2.1x = 346.50

          x = 165

so they sold 165 slices of pizza.