Find f(g(x)) f(x)=(x-5)/2 g(x)=2x+5

$f (x) = \frac{x - 5}{2}$ $g (x) = 2 x + 5$

Set up the composite result function.

$f (g (x))$

Evaluate $f (2 x + 5)$ by substituting in the value of $g$ into $f$ .

$f (2 x + 5) = \frac{(2 x + 5) - 5}{2}$

Simplify the numerator.

Subtract $5$ from $5$ .

$f (2 x + 5) = \frac{2 x + 0}{2}$

Add $2 x$ and $0$ .

$f (2 x + 5) = \frac{2 x}{2}$

Cancel the common factor of $2$ .

Cancel the common factor.

$f (2 x + 5) = \frac{2 x}{2}$

Divide $x$ by $1$ .

$f (2 x + 5) = x$