Tap the blue circles to see an explanation.
$$ \begin{aligned}-4\sqrt{50}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-4\cdot \sqrt{ 25 \cdot 2 } \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-4\cdot \sqrt{ 25 } \cdot \sqrt{ 2 } \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}-4\cdot5 \sqrt{ 2 } \xlongequal{ } \\[1 em] & \xlongequal{ }-20\sqrt{2}\end{aligned} $$ | |
① | Factor out the largest perfect square of 50. ( in this example we factored out $ 25 $ ) |
② | Rewrite $ \sqrt{ 25 \cdot 2 } $ as the product of two radicals. |
③ | The square root of $ 25 $ is $ 5 $. |