Tap the blue circles to see an explanation.
$$ \begin{aligned}\sqrt{63}+6\sqrt{28}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}3\sqrt{7}+12\sqrt{7} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}15\sqrt{7}\end{aligned} $$ | |
① | $$ \sqrt{63} =
\sqrt{ 3 ^2 \cdot 7 } =
\sqrt{ 3 ^2 } \, \sqrt{ 7 } =
3 \sqrt{ 7 }$$ |
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 |