Find f(g(x)) f(x)=3x+5 , g(x)=x+7

$f (x) = 3 x + 5$ , $g (x) = x + 7$

Step 1

Set up the composite result function.

$f (g (x))$

Step 2

Evaluate $f (x + 7)$ by substituting in the value of $g$ into $f$ .

$f (x + 7) = 3 (x + 7) + 5$

Step 3

Simplify each term.

Apply the distributive property.

$f (x + 7) = 3 x + 3 \cdot 7 + 5$

Multiply $3$ by $7$ .

$f (x + 7) = 3 x + 21 + 5$

Step 4

Add $21$ and $5$ .

$f (x + 7) = 3 x + 26$