Pre-Algebra Examples

$f (x) = \frac{x - 9}{x^{2} - 9}$

Step 1

Rewrite the function as an equation.

$y = \frac{x - 9}{x^{2} - 9}$

Step 2

Simplify the denominator.

Tap for more steps...

Step 2.1

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

$y = \frac{x - 9}{x^{2} - 3^{2}}$

Step 2.2

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 $b = 3$ .

$y = \frac{x - 9}{(x + 3) (x - 3)}$