Without using a graphing utility, find all the roots of the following polynomials. You may use whatever techniques you want to. There are many different approaches.

a) f(x)=5x^5−5x^4+12x^3−24x^2+32x−16
b) g(x)=x^5−x^4+x^3−2x+2
c) h(x)=x^3+8x^2+11x−20
d) k(x)=4x^5−8x^4−x+2