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

1 Answer
Jan 20, 2017

Answer:

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 #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.
For example, in your case:
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.