Question 64234
Call the number of pizza x. The number of hamburgers must be 2x + 2.
The cost of pizzas at $6 will be 6x and the cost of hamburgers at $2 will be 2(2x + 2)
The cost should therefore be
6x + 2(2x + 2) = 84
6x + 4x + 4 = 84
10x + 4 = 84
10x + 4 - 4 = 84 - 4
10x = 80
x = 8
so 8 pizzas were purchased and 18 hamburgers