Final answer:
To find f(gx), substitute gx into the function f(x) = 2x and simplify.
Step-by-step explanation:
To find f(gx), we first substitute gx into the function f(x) = 2x. This gives us f(gx) = 2(gx). Next, we substitute the function g(x) = x + 5 into gx, obtaining gx = x + 5. Finally, we substitute this result into f(gx), which gives us f(gx) = 2(x + 5).
Expanding the expression, we get f(gx) = 2x + 10. Therefore, option A) f(gx) = 2x + 5 is incorrect. The correct answer is A) f(gx) = 2x + 10.