# How do you find the excluded value of 3/(x-5)?

Jan 20, 2017

I got $x = 5$

#### Explanation:

You need to consider the value of $x$ that makes your fraction impossible to be evaluated; the only option is when $x = 5$. This is because you would get $\frac{1}{0}$ that you cannot evaluate!
So, when you have a fraction with unknown in it (in the denominator) always set the denominator equal to zero, solve it as a normal equation and exclude the value(s) of the unknown you find.
1) take the denominator: $x - 5$;
2) set it equal to zero: $x - 5 = 0$;
3) solve the equation: $x = 5$;
Now you can exclude the result, $x = 5 ,$ from the set of values you can use into your fraction.