| $$ \begin{aligned}(x^2+xy)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}x^4+2x^3y+x^2y^2\end{aligned} $$ | |
| ① | Find $ \left(x^2+xy\right)^2 $ using formula. $$ (A + B)^2 = \color{blue}{A^2} + 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ x^2 } $ and $ B = \color{red}{ xy }$. $$ \begin{aligned}\left(x^2+xy\right)^2 = \color{blue}{\left( x^2 \right)^2} +2 \cdot x^2 \cdot xy + \color{red}{\left( xy \right)^2} = x^4+2x^3y+x^2y^2\end{aligned} $$ |