Question

Simplify. square root of 3 times square root of 21

Answer 1

Having this:
\[\sqrt{3}\sqrt{21}\]
I already proven the equality three times, so I will just write it:
\[\sqrt[n]{a}\sqrt[n]{b}=\sqrt[n]{a.b}\]
"a" and "b" are real numbers or variables, and "n" as well.
So meaning that if I have the radical of any index multiplied by another radical of the same index but a different numebr inside, is the same as multiplying the numbers inside one whole radical.
So, if we have:
\[\sqrt{3}\sqrt{21}=\sqrt{3.21}\]
having applied the property, now I'll let you multiply and finish the exercise.