Question 942542

the opposite of {{{6x^2-3x-7x}}} is {{{-(6x^2-3x-7x)}}} or {{{-6x^2+3x+7x}}}

In addition and subtraction the opposites combined make {{{0}}}. 

If you add  {{{-(6x^2-3x-7x) + (6x^2-3x-7x)}}}  it turns the first one into {{{-6x^2+3x+7x + 6x^2-3x-7x}}}and this would equal {{{0}}}.