# For what values of y is the function undefined: y=(2x-5)/(x+3)?

Mar 17, 2017

See the explanation

#### Explanation:

If a function in $x$ is undefined then $y$ can not take on a value.

If $y$ can take on a value then the function is defined.

$y = \frac{2 x - 5}{x + 3}$ is undefined at $x = - 3$

If this were to be the case we would have

$y = \frac{- 6 - 5}{0}$ you are 'not allowed' to have 0 as a denominator. Hence 'undefined'