Final answer:
The expression to calculate the total cost of renting a truck is C(m) = 50 + 0.99m, where C(m) is the total cost and m is the miles driven.
Step-by-step explanation:
The student is asking for an expression to calculate the total cost of renting a truck, where the cost consists of a fixed charge plus a variable charge based on the miles driven. The fixed charge for renting the truck is $50, and there is an additional charge of $0.99 for each mile the truck is driven. To determine the total cost, we use the expression C(m) = 50 + 0.99m, where C(m) represents the total cost in dollars and m represents the number of miles driven.