| $$ \begin{aligned}(isqrt\cdot7)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}49i^2q^2r^2s^2t^2\end{aligned} $$ | |
| ① | $$ \left( 7iqrst \right)^2 = 7^2i^2q^2r^2s^2t^2 = 49i^2q^2r^2s^2t^2 $$ |