Question
Answer
$$-7\sqrt{63}-6\sqrt{28}=-33\sqrt{7}$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}-7\sqrt{63}-6\sqrt{28}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-21\sqrt{7}-12\sqrt{7} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}-33\sqrt{7}\end{aligned} $$ | |
| ① | $$ - 7 \sqrt{63} =
-7 \sqrt{ 3 ^2 \cdot 7 } =
-7 \sqrt{ 3 ^2 } \, \sqrt{ 7 } =
-7 \cdot 3 \sqrt{ 7 } =
-21 \sqrt{ 7 } $$ |
| ② | $$ - 6 \sqrt{28} =
-6 \sqrt{ 2 ^2 \cdot 7 } =
-6 \sqrt{ 2 ^2 } \, \sqrt{ 7 } =
-6 \cdot 2 \sqrt{ 7 } =
-12 \sqrt{ 7 } $$ |
| ③ | Combine like terms |
This page was created using
Simplify Radical Expression