Question

For which value(s) of x will the rational expression below be undefined?
Check all that apply.
(x-3)(x+6)
x + 7

Answer 1

Question:

For which value(s) of x will the rational expression below be undefined? Check all that apply.

(x-3)(x+6)/x+7

Answer:

For x = -7 the rational expression is undefined

Solution:

Given rational expression is:

$\dfrac{(x-3)(x+6)}{(x+7)}$

We have to find the value of x for which the rational expression becomes undefined

A rational expression is undefined when the denominator is equal to zero

Here, the denominator becomes zero when x = -7

Substitute x = -7 in given

$\dfrac{(-7-3)(-7+6)}{(-7+7)} = \frac{-10 \times -1}{0} = \frac{10}{0}$

Thus for x = -7 the rational expression is undefined