Final answer:
The equation that can be used to calculate how much Drew pays for his gym membership is Cost = $34x.
Step-by-step explanation:
The equation that can be used to calculate how much Drew pays for his gym membership is Cost = $34x. Option C is the correct answer.
This equation represents a simple multiplication, where $34 is multiplied by the number of months x to determine the total cost of Drew's gym membership.
For example, if Drew has a gym membership for 3 months, the total cost would be $34 x 3 = $102.