Question 920405
{{{f(x)=x^4+x^3+7x^2+9x-18}}}...write {{{7x^2}}} as {{{-2x^2+9x^2}}}


{{{f(x)=x^4+x^3-2x^2+9x^2+9x-18}}}...group


{{{f(x)=(x^4+x^3-2x^2)+(9x^2+9x-18)}}}


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


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


{{{f(x)=(x-1)(x+2)(x^2+9)}}}