Precalculus Examples

If $f (x) = x + 7$ and $g (x) = 3 x - 5$ ; what is $(f + g) (x)$ ?

Step 1

Evaluate $f + g$ .

Tap for more steps...

Step 1.1

Replace the function designators in $f + g$ with the actual functions.

$x + 7 + 3 x - 5$

Step 1.2

Remove parentheses.

$x + 7 + 3 x - 5$

Step 1.3

Add $x$ and $3 x$ .

$4 x + 7 - 5$

Step 1.4

Subtract $5$ from $7$ .

$4 x + 2$

Step 2

Evaluate $f + g$ at $x$ .

$4 (x) + 2$

Step 3

Simplify $4 (x) + 2$ .

Tap for more steps...

Step 3.1

Remove parentheses.

$4 (x) + 2$

Step 3.2

Multiply $4$ by $x$ .

$4 x + 2$