Question
Answer
$$-7\sqrt{80}=-28\sqrt{5}$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}-7\sqrt{80}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-7\cdot \sqrt{ 16 \cdot 5 } \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-7\cdot \sqrt{ 16 } \cdot \sqrt{ 5 } \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}-7\cdot4 \sqrt{ 5 } \xlongequal{ } \\[1 em] & \xlongequal{ }-28\sqrt{5}\end{aligned} $$ | |
| ① | Factor out the largest perfect square of 80. ( in this example we factored out $ 16 $ ) |
| ② | Rewrite $ \sqrt{ 16 \cdot 5 } $ as the product of two radicals. |
| ③ | The square root of $ 16 $ is $ 4 $. |
This page was created using
Simplify Radical Expression