Factor 36-4x^2

$36 - 4 x^{2}$

Step 1

Factor $4$ out of $36 - 4 x^{2}$ .

Factor $4$ out of $36$ .

$4 (9) - 4 x^{2}$

Factor $4$ out of $- 4 x^{2}$ .

$4 (9) + 4 (- x^{2})$

Factor $4$ out of $4 (9) + 4 (- x^{2})$ .

$4 (9 - x^{2})$

Step 2

Rewrite $9$ as $3^{2}$ .

$4 (3^{2} - x^{2})$

Step 3

Factor.

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 3$ and $b = x$ .

$4 ((3 + x) (3 - x))$

Remove unnecessary parentheses.

$4 (3 + x) (3 - x)$