Because as u get into intermdiate and college algebra in college you have to know these things to solve other equations such as setting ur answer to Zero after u get ur factorization answer. Only if you are starting pre-algebra is why someone would be asking this. But if ur already in college algebra and asking this then my answer doesnt apply to you.
We can't answer that without knowing what the polynomial is.
90
12
Start by looking for a common factor. Separate this factor, then factor the remaining polynomial.
(11x-1)(11x-1)
13x(x+3x)
-(x + 5)(x + 6)
(x + 9)(x + 2)
5(x - 5)(x - 2)
(x + 5)(x + 2)
It is 6x(2x+5) when factored
If the cubic polynomial you are given does not have an obvious factorization, then you must use synthetic division. I'm sure wikipedia can tell you all about that.