Question

Simplify completely
x2 + 4x - 45
and find the restrictions on the variable.

Answer 1

(x-5)/(x+1) and x cannot equal -1 because the denominator can't be zero.

Explanation:

Factor the numerator:

(x+9)(x-5)

Factor the denominator:

(x+1)(x+9)

So you have

(x+9)(x-5)/(x+1)(x+9); see that you can cross out the (x+9) in both the numerator and denominator?

You're left with (x-5)/(x+1)

The only number that is restricted is -1, because that would make the denominator zero, which is a no no!!