Question

If f(1) = 5, which expression could represent f (x)?

A- 3x(2) + 14x + 8
B- 3x(2) - 14x - 8
C- 3x(2) + 10x -8
D- 3x(2) - 10x -8

Answer 1

If f(1) = 5, then you can find your answer by substituting 1 in for x in all of the options to figure out which one gives you 5 as a result.

A: 3(1)^2 + 14(1) + 8 = 25 ≠ 5 Nope

B: 3(1)^2 - 14(1) - 8 = -19 ≠ 5 Nope

C: 3(1)^2 + 10(1) - 8 = 5 Yup

D: 3(1)^2 - 10(1) - 8 = -15 Nope

Only C fits f(1) = 5.