Question

Multiple and simplify by factoring
√6 . √21

Answer 1

The way to do these is to split each number into its prime factors. so:
6 = 2*3
21 = 3*7

Then you can do:\[\sqrt{6}*\sqrt{21}=\sqrt{6*21}=\sqrt{2*3*3*7}=\sqrt{3^2*2*7}=3\sqrt{2*7}=3\sqrt{14}\]