Question 105600
Definition:

Additive Inverse {{{-a }}}is the additive inverse of {{{a}}}: {{{a+(-a )=0}}}
If {{{A =6x^2+x}}}
Find additive inverse {{{B}}}
Solution: To obtain the additive inverse {{{B}}} of {{{A}}}, write the additive inverses of each of the coefficients of its terms. 
In your case, that is {{{-6}}}, {{{-1}}},are the coefficients of the terms in the polynomial {{{B}}} respectively.

So, the additive inverse {{{B =-6x^2 }}} {{{- x}}}