Question

The zero of the polynomial x^{3} -3x^{2} -5x+15[/tex].

Answer 1

factoring:

x^2(x-3)-5(x-3)

x^2-5(x-3)

x-3=0

x=3

x^2-5=0

x=±(√5)

so the zeros are 3,-(√5),+(√5)