# How do you simplify and find the excluded value of (X^2+3x-10)/(x^2+x-20)?

Feb 11, 2017

$\frac{x - 2}{x - 4}$; the excluded value is $x = - 5$

#### Explanation:

Since

${x}^{2} + 3 x - 10 = \left(x + 5\right) \left(x - 2\right)$

and

${x}^{2} + x - 20 = \left(x + 5\right) \left(x - 4\right)$

the expression is:

$\frac{{x}^{2} + 3 x - 10}{{x}^{2} + x - 20} = \frac{\textcolor{red}{\left(x + 5\right)} \left(x - 2\right)}{\textcolor{red}{\left(x + 5\right)} \left(x - 4\right)}$

Then the excluded value is $x = - 5$

and you can simplify to:

$\frac{x - 2}{x - 4}$