Answer:
9 Pizzas.
Step-by-step explanation:
Since Sam has $150 in total, and already spent $40 on drinks, we need to deduct that from the total ($150 - $40), in turn leaving us with $110. Since we aren't sure of the amount of pizzas bought yet, lets use the variable x in its place. Since each pizza costs $12, we need to use $12(x) = $110, $110 again being the total after Sam bought the drinks. After dividing $110 by $12, we are left with 9 pizzas, with $2 extra. Therefore, he can buy 9 pizzas.