Final answer:
The expression (f + g)(4) is equivalent to f(4) + g(4).
Step-by-step explanation:
The expression (f + g)(4) represents the sum of the functions f and g evaluated at x = 4. To find an equivalent expression, we need to evaluate f(4) and g(4) separately and then add them together. Therefore, the correct expression is option a. f(4) + g(4).