# What is the value of g[f(4)] for the functions f(x) = 2x + 1 and g(x) = 2x - 5?

Aug 4, 2016

$= 13$

#### Explanation:

$f \left(x\right) = 2 x + 1$
or
$f \left(4\right) = 2 \left(4\right) + 1$
or
$f \left(4\right) = 8 + 1$
or
$f \left(4\right) = 9$
$g \left(x\right) = 2 x - 5$
or
$g \left[f \left(4\right)\right] = g \left(9\right)$
or
$g \left(9\right) = 2 \left(9\right) - 5$
or
$g \left(9\right) = 18 - 5$
or
$g \left(9\right) = 13$