Final answer:
The cost of labor for Certified Remodeling if they work for 10 hours is $75.
Step-by-step explanation:
The function C(x) = 25 + 5x represents the labor cost in dollars for Certified Remodeling to build a deck, where x is the number of hours of labor. To find the cost of labor for Certified Remodeling if they work for 10 hours, we substitute x = 10 into the function C(x).
C(10) = 25 + 5(10) = 25 + 50 = 75
Therefore, the cost of labor for Certified Remodeling if they work for 10 hours is $75.