9
Answer: CSet 3: Function Notation (Advanced)
Explanation
PROBLEM
If f(x) = 5x - 1, find x when f(x) = 19.
If f(x) = 5x - 1, find x when f(x) = 19.
A.
5
B.
7
C.✓ Correct
4
D.
6
Detailed Explanation
Choice C is the best answer. 5x - 1 = 19. 5x = 20. x = 4
Why others are wrong:
A: 5 is incorrect because it does not satisfy the equation.
B: 7 is incorrect because it does not satisfy the equation.
D: 6 is incorrect because it does not satisfy the equation.