Mario's Pizza just received two big orders from customers throwing parties. The first customer, Vincent, bought 4 regular pizzas and 6 deluxe pizzas and paid $152. The second customer, Ronald, ordered 4 regular pizzas and 3 deluxe pizzas, paying a total of $92. What is the price of each pizza?

Question

Mario's Pizza just received two big orders from customers throwing parties. The first customer, Vincent, bought 4 regular pizzas and 6 deluxe pizzas and paid $152. The second customer, Ronald, ordered 4 regular pizzas and 3 deluxe pizzas, paying a total of $92. What is the price of each pizza?

Answer 1

4r + 6d = 152

4r + 3d = 92

6d + 4r = 152
3d + 4r = 92
6d + 4r - (3d + 4r) = 152 - 92
6d + 4r - 3d - 4r = 152 - 92
6d - 3d = 152 - 92
d = 20

3 * 20 + 4r = 92
r = 8