Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrr} & -4x^2 & -5x & -1 \\ \color{blue}{ + } & 4x^2 & -6x & -2 \\ \hline \end{array} $$Step 2: Combine like terms (add each column):
$$ \begin{array}{lrrr} & -4x^2 & -5x & -1 \\ \color{blue}{ + } & 4x^2 & -6x & -2 \\ \hline & & -11x & -3 \end{array} $$