Solve for f(x) and g(x) individually. You may have other variables rather than "f" and "g," but the process would still be the same.
Multiply the two solutions derived from solving each individual function.
Consider the following practice problem: f(x) = 3x and g(x) = 5x + 2. What is f(8) times g(2)? The first step to solving this problem is substituting the 9 with the "x" in the function f(x), so f(8) = 3(8) = 24. Solving for g(2) yields g(2) = 5(2) + 2 = 12. Complete the problem by multiplying 24 x 12 = 288.