| $$ \begin{aligned}1-x-0.11x^2& \xlongequal{ }1-x-0x^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-x+1\end{aligned} $$ | |
| ① | Combine like terms: $$ -x+1 = -x+1 $$ |