Question 118865


{{{2x^2-162}}}...divide both terms by {{{2}}}

{{{(2x^2)/2-162/2}}}...

{{{(cross(2)x^2)/2-cross(2)*81/cross(2)}}}...

{{{x^2-81}}}...

{{{x^2-9^2}}}...

{{{(x-9)(x+9)}}}...