Question 149902
(x^2-16)/(x2+3x-4)
.
Factoring the numerator:
[(x+4)(x-4)]/(x2+3x-4)
.
Factoring the denominator:
[(x+4)(x-4)]/[(x+4)(x-1)]
NOTICE, the entire expression is "undefined" if the denominator goes to zero.  It will be zero if x = {-4, 1}
.
Going back to:
[(x+4)(x-4)]/[(x+4)(x-1)]
Canceling out the (x+4) we get our solution of:
(x-4)/(x-1)  
if x DOES NOT equal -4 or 1