How do you simplify and find the excluded value of (x^2 – 7x + 12)/( x^2 – 16) ?

Apr 16, 2017

We can factor both terms:

Explanation:

$= \frac{\left(x - 3\right) \left(x - 4\right)}{\left(x + 4\right) \left(x - 4\right)}$

Provided the denominator is $\ne 0$ we may cancel:

$= \frac{\left(x - 3\right) \cancel{\left(x - 4\right)}}{\left(x + 4\right) \cancel{\left(x - 4\right)}} = \frac{x - 3}{x + 4}$

The excluded values are $x = + 4 \mathmr{and} x = - 4$