One pizza costs $9 and a 2-liter of soda costs $2. The expression 9p + 2s represents the cost of buying p pizzas and s sodas. What would the total cost be for buying four pizzas and two sodas?
To find the total cost for buying four pizzas and two sodas, we substitute p=4 and s=2 into the expression 9p + 2s:
9(4) + 2(2) = 36 + 4 = $<<36+4=40>>40. Answer: \boxed{40}.