Algebra Examples

$x^{2} - 81$

Step 1

Rewrite $81$ as $9^{2}$ .

$x^{2} - 9^{2}$

Step 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 $b = 9$ .

$(x + 9) (x - 9)$

$[\begin{array}{c} x^{2} & \frac{1}{2} \\ \sqrt{π} & \int x d x \end{array}]$