| $$ \begin{aligned}-\sqrt{35}-\sqrt{-35}& \xlongequal{ }-\sqrt{35}-\sqrt{35}\cdot i \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(-1-i)\sqrt{35}\end{aligned} $$ | |
| ① | Use the distributive property. |