Set 3: Linear Functions (Beginner)

**Choice B is the best answer.** f(9) = 3(9) = 27

Explanation

Answer: B

PROBLEM

If f(x) = 3x, find f(9).

✓ Correct

Detailed Explanation

Choice B is the best answer. f(9) = 3(9) = 27

Why others are wrong:

A: 21 is incorrect because it does not satisfy the equation.

C: 12 is incorrect because it does not satisfy the equation.

D: 30 is incorrect because it does not satisfy the equation.