Question

Find each function value.

a. f(5) if f(x) = 3x + 4

b. f(-3) if f(x) = 2x - 8

c. f(7) if f(x) = 9x - 24

Answer 1

a) f(5) = 3(5) + 4 = 19
b) f(-3) = 2(-3) - 8 = -14
c) f(7) = 9(7) - 24 = 39

Substitute 5, -3, and 7 for x.

Answer 2

If f(x) = 3x + 4

f(5) = 3(5) + 4 = 15 + 4 = 19

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If f(x) = 2x - 8

f(-3) = 2(-3) - 8 = - 6 - 8 = -14

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If f(x) = 9x - 24

f(7) = 9(7) - 24 = 63 - 24 = 39