Question 977234

{{{f(x)=x^3+3x^2-9x-27}}}

{{{f(x)=(x^3+3x^2)-(9x+27)}}}

{{{f(x)=x^2(x+3)-9(x+3)}}}

{{{f(x)=(x^2-9)(x+3)}}}

{{{f(x)=(x^2-3^2)(x+3)}}}

{{{f(x)=(x-3)(x+3)(x+3)}}}

set {{{f(x)=0}}}

{{{0=(x-3)(x+3)(x+3)}}}

if {{{0=(x-3)}}}=>{{{x=3}}}
if{{{0=(x+3)}}}=>{{{x=-3}}} multiplicity {{{2}}}

so, zeros are:({{{x[1]}}},{{{x[2]}}},{{{x[3]}}})=({{{3}}},{{{-3}}},{{{-3}}})