What is the square root of 10 times the square root of 20?

1 Answer
Sep 9, 2015

10sqrt(2)102

Explanation:

You need to multiply sqrt(10)10 and sqrt(20)20.

Before doing that, take a look at sqrt(20)20. Notice that you can write it as

sqrt(20) = sqrt(2 * 10)20=210

If you use the product property of radicals, which tells you that

color(blue)(sqrt(a * b) = sqrt(a) * sqrt(b))ab=ab

you can write

sqrt(2 * 10) = sqrt(2) * sqrt(10)210=210.

Your expression will now be

sqrt(10) * sqrt(2) * sqrt(10) = sqrt(2) * sqrt(10) * sqrt(10)10210=21010

=sqrt(2) * sqrt(10 * 10) = sqrt(2) * sqrt(100)=21010=2100

= sqrt(2) * 10 = color(green)(10sqrt(2))=210=102