Question 39588
{{{x^4 - 18x^2 + 81}}} find factors of the product of the leading coefficient and the constant that sum up to {{{-18}}}
They are: {{{-9}}} and {{{-9}}}
{{{x^4 - 9x^2 - 9x^2 + 81}}}
{{{(x^4 - 9x^2) + (- 9x^2 + 81)}}}
{{{(x^2)(x^2 - 9) - 9(x^2 - 9)}}}
{{{(x^2 - 9)(x^2 - 9)}}}