Simplify the rational expression. State any restrictions on the variable. (t^2 + 4t - 12)/(t^2 - 4)

my answer sheet says:
(t + 6)/(t + 2), t ≠ 2, t ≠ –2

is the correct answer, I don't understand how there is a restriction on +2 ?

Question

Simplify the rational expression. State any restrictions on the variable. (t^2 + 4t - 12)/(t^2 - 4)

my answer sheet says:
(t + 6)/(t + 2), t ≠ 2, t ≠ –2

is the correct answer, I don't understand how there is a restriction on +2 ?

hoblos · Answer

do you know how to factorize   t^2 + 4t - 12    and    t^2 - 4    ?

anonymous · Answer

yes i understand how to factor that, but what I don't understand is why is there a restriction for t = 2. I though restrictions only happen with the denominator is 0

hoblos · Answer

in the denominator we have 
 t^2 - 4 = (t-2)(t+2)
so both (t-2) and (t+2) must be different than zero

anonymous · Answer

oh ok thanks!

hoblos · Answer

any time :)