Factor x^2-100

$x^{2} - 100$

Rewrite $100$ as $10^{2}$ .

$x^{2} - 10^{2}$

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = x$ and $b = 10$ .

$(x + 10) (x - 10)$