Question 134946
{{{x^3-5x^2+4x-20=0}}} Start with the given equation


{{{(x^3-5x^2)+(4x-20)=0}}} Group like terms



{{{x^2(x-5)+4(x-5)=0}}} Factor out the GCF {{{x^2}}} out of the first group. Factor out the GCF {{{4}}} out of the second group



{{{(x^2+4)(x-5)=0}}} Since we have the common term {{{x-5}}}, we can combine like terms



Now set each factor equal to zero:


{{{x^2+4=0}}} or  {{{x-5=0}}} 


Now solve for x for each factor:


{{{x=-2i}}}, {{{x=2i}}} or  {{{x=5}}}