Tap the blue circles to see an explanation.
$$ \begin{aligned}3\sqrt{45}-2\sqrt{5}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}9\sqrt{5}-2\sqrt{5} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}7\sqrt{5}\end{aligned} $$ | |
① | $$ 3 \sqrt{45} =
3 \sqrt{ 3 ^2 \cdot 5 } =
3 \sqrt{ 3 ^2 } \, \sqrt{ 5 } =
3 \cdot 3 \sqrt{ 5 } =
9 \sqrt{ 5 } $$ |
② | Combine like terms |