| $$ \begin{aligned}sqrt(4x-4)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}4qrstx-4qrst\end{aligned} $$ | |
| ① | Multiply $ \color{blue}{qrst} $ by $ \left( 4x-4\right) $ $$ \color{blue}{qrst} \cdot \left( 4x-4\right) = 4qrstx-4qrst $$ |