Tap the blue circles to see an explanation.
$$ \begin{aligned}-6\sqrt{80}-\sqrt{5}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-24\sqrt{5}-\sqrt{5} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-25\sqrt{5}\end{aligned} $$ | |
① | $$ - 6 \sqrt{80} =
-6 \sqrt{ 4 ^2 \cdot 5 } =
-6 \sqrt{ 4 ^2 } \, \sqrt{ 5 } =
-6 \cdot 4 \sqrt{ 5 } =
-24 \sqrt{ 5 } $$ |
② | Combine like terms |