Let f(x) = -3x - 4 and g(x) = 2x - 6. Find (f o g) (-7) A. 28 B. -20 C. 17 D. 56

Mathematics · High School · Mon Jan 18 2021

Answered on

Given the function:

Let f(x) = -3x - 4 and g(x) = 2x - 6. 

Find (f o g)

Solution:

The given condition is a composition of a function, whereas we substitute the value of g(x) to f(x).

(f o g) = -3(2x - 6) - 4

(f o g) = -6x + 18 - 4

(f o g) = -6x + 14

(f o g)(-7) = -6(-7) + 14

(f o g)(-7) = 42 + 14

(f o g)(-7) =  56

Final answer:

D. 56