+227 Well, here we go.
$$\frac{\sqrt{21}}{\sqrt{7}} = \frac{\sqrt{7}*\sqrt{3}}{\sqrt{7}} = \sqrt{3}$$
What just happened here? Well, I took the 21 from under the radical and split it up into two other radicals. This works, because $$\sqrt{a}*\sqrt{b}=\sqrt{a*b}$$.
So, I broke it up. The two √7 's cancel out, leaving √3 as the answer.
+227 Well, here we go.
$$\frac{\sqrt{21}}{\sqrt{7}} = \frac{\sqrt{7}*\sqrt{3}}{\sqrt{7}} = \sqrt{3}$$
What just happened here? Well, I took the 21 from under the radical and split it up into two other radicals. This works, because $$\sqrt{a}*\sqrt{b}=\sqrt{a*b}$$.
So, I broke it up. The two √7 's cancel out, leaving √3 as the answer.
