Question

1. Given f(x) = 3x – 4 and g(x)=–2x+7 evaluate:
(fog)(5)

Answer 1

(f o g)(5) = -13

General Formulas and Concepts:

Pre-Alg

• Order of Operations: BPEMDAS

Algebra I

• Composition of functions

Explanation:

Step 1: Define

f(x) = 3x - 4

g(x) = -2x + 7

(f o g)(5) is f(g(5))

Step 2: Find composite function

1. Substitute: (f o g)(x) = 3(-2x + 7) - 4
2. Distribute: (f o g)(x) = -6x + 21 - 4
3. Combine like terms: (f o g)(x) = -6x + 17

Step 3: Solve

1. Substitute: (f o g)(5) = -6(5) + 17
2. Multiply: (f o g)(5) = -30 + 17
3. Add: (f o g)(5) = -13