(x3 - 1)/(x3+4)
Let's recall the following rules for factoring cubics.
a3 - b3 = (a-b)(a2 + ab + b2)
a3 + b3 = (a+b)(a2 - ab + b2)
With these in mind, let first factor the numerator
x3 - 1 = (x-1)(x2+x+1)
and the denominator
x3 + 4 = (x+2)(x2-2x+4)
(x-1) (x2+x+1)
(x+2)(x2-2x+4)
Hope this helps.
Mark M.
12/29/15