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