Advanced Math practice question

Answer: B. 11

Work inside out: g(4) = 2(4) = 8, then f(8) = 8 + 3 = 11. Choice C reverses the order as g(f(4)); composition is not commutative.

Why the other answers are wrong

A. 8

You computed g(4) = 8 and stopped. That's the inside step — now substitute it into f: f(8) = 8 + 3 = 11.

C. 14

You reversed the order and found g(f(4)) = 2(4 + 3) = 14. In f(g(4)), g runs first, then f.

D. 20

No single step of this composition produces 20 — evaluate inside out: g(4) = 8, then f(8) = 8 + 3 = 11.

More Advanced Math questions

• Medium
  What are the solutions to x² − 5x + 6 = 0?
• Medium
  The graph of f(x) = (x − 3)² + 4 is a parabola. What are the coordinates of its vertex?
• Medium
  If x² − 2x − 8 = (x + 2)(x − a), what is the value of a?
• Medium
  If √(x + 5) = 4, what is the value of x?
• Medium
  What are the solutions to x² + 6x + 8 = 0?
• Medium
  The system y = x² and y = x + 6 has two solutions. What is the sum of the two x-values of those solutions?