How do you simplify #3sqrt20 + 2sqrt45#?

1 Answer
May 1, 2016

#12sqrt5#

Explanation:

In most questions involving powers and roots, a good strategy is to break numbers down into their prime factors. This tells us what we are working with.

#3sqrt(4xx5) + 2 sqrt(9xx5)#

4 and 9 are square numbers, they have exact square roots.

= #3xx2sqrt(5) + 2xx3 sqrt(5)#

= #6sqrt(5) + 6sqrt(5)#

= #12sqrt5#