Answer :
so... get the like-terms and add/subtract [tex]7x^2-13x-2+27x^2-6x-1
\\ \quad \\
\textit{add/subtract the like-terms}
\\ \quad \\
\boxed{7x^2+27x^2}\quad \boxed{-13x-6x}\quad \boxed{-1-2}[/tex]
see what that gives you
see what that gives you