Question

Divide: $18\sqrt{21}$ by $6\sqrt{7}$.

Answer 1

On dividing $18\sqrt{21}$ by $6\sqrt{7}$:

Here $18\sqrt{21}$ by $6\sqrt{7}$ can be written as,

$=\frac{18\sqrt{21}}{6\sqrt{7}}$

18 is a multiple of 6 so we can divide it.

$=\frac{3\sqrt{21}}{\sqrt{7}}$

$$\begin{gathered} =\frac{3\times \sqrt{3\times 7}}{\sqrt{7}} \\ =\frac{3\times \sqrt{3}\times \sqrt{7}}{\sqrt{7}} \\ =3\sqrt{3} \end{gathered}$$

Hence, $18\sqrt{21}$ by $6\sqrt{7}$ is $3\sqrt{3}$.