Tap the blue circles to see an explanation.
| $$ \begin{aligned}-6\sqrt{126}+7\sqrt{14}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-18\sqrt{14}+7\sqrt{14} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-11\sqrt{14}\end{aligned} $$ | |
| ① | $$ - 6 \sqrt{126} =
-6 \sqrt{ 3 ^2 \cdot 14 } =
-6 \sqrt{ 3 ^2 } \, \sqrt{ 14 } =
-6 \cdot 3 \sqrt{ 14 } =
-18 \sqrt{ 14 } $$ |
| ② | Combine like terms |