Precalculus Examples

$f (x) = 3 x^{2} + 7 x$ and $g (x) = 2 x^{2} - x - 1$ ; find $(f + g) (x)$

Step 1

Evaluate $f + g$ .

Tap for more steps...

Step 1.1

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

$3 x^{2} + 7 x + 2 x^{2} - x - 1$

Step 1.2

Remove parentheses.

$3 x^{2} + 7 x + 2 x^{2} - x - 1$

Step 1.3

Add $3 x^{2}$ and $2 x^{2}$ .

$5 x^{2} + 7 x - x - 1$

Step 1.4

Subtract $x$ from $7 x$ .

$5 x^{2} + 6 x - 1$

Step 2

Evaluate $f + g$ at $x$ .

$5 {(x)}^{2} + 6 (x) - 1$

Step 3

Simplify $5 {(x)}^{2} + 6 (x) - 1$ .

Tap for more steps...

Step 3.1

Remove parentheses.

$5 {(x)}^{2} + 6 (x) - 1$

Step 3.2

Multiply $6$ by $x$ .

$5 x^{2} + 6 x - 1$