### Home > CC4 > Chapter 1 > Lesson 1.2.3 > Problem1-61

1-61.

Calculate f(4) for each function below. Homework Help ✎

1. $f ( x ) = x - 3$

Substitute 4 in for the variable x.
So f(4) = 4 − 3.

1. $f ( x ) = ( \frac { 1 } { 5 } ) ^ { x }$

${f(4)=\left ( \frac{1}{5} \right )^{4}= \frac{1^{4}}{5^{4}}= \frac{1}{625}}$

1. $f ( x ) = 3 x - 12$

Substitute 4 in for the variable x.

1. $f ( x ) = ( x - 2 ) ^ { 3 } - 6$

Substitute 4 in for the variable x.

${{f\left ( 4 \right )=\left ( 4 - 2 \right )^{3} - 6}}$

${f\left ( 4 \right )=\left ( 2 \right )^{3}-6}$

${f\left ( 4 \right )=8-6}$

${f\left ( 4 \right )=2}$