Question 1100968
{{{x^2(x^2+49)}}}


If you look at the quadratic factor {{{x^2+49=0}}}
{{{x^2=-49}}}
{{{x=0+- sqrt(-49)}}}
{{{x=0+- 7i}}}



{{{x^2(x^2+49)}}}
{{{highlight(x^2(x-7i)(x+7i))}}}