# How do you find k(4-x) given k(x)=4x-4?

Aug 27, 2016

$k \left(4 - x\right) = 12 - 4 x$

#### Explanation:

Given:

$k \left(x\right) = 4 x - 4$

The variable $x$ can be replaced by any other variable, e.g. $t$...

$k \left(t\right) = 4 t - 4$

Now substitute $4 - x$ for $t$ to find:

$k \left(4 - x\right) = 4 \left(4 - x\right) - 4$

$= 16 - 4 x - 4$

$= 12 - 4 x$