Question 553043
You must first find the largest perfect square that is a factor of 120 in the square root sign.  This would be 4, so break down the 120=4*30


{{{-3*sqrt(120)}}}
{{{-3*sqrt(4)*sqrt(30)}}}
{{{-3*2*sqrt(30)}}}
{{{-6*sqrt(30)}}}


I have a REALLY good explanation of square roots on my website.  You can find my website by use of the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com.  At the bottom of this page is a link that will take you to my FREE Homepage.  Look near the top of this page for the link "Basic, Intermediate, and College Algebra: One Step at a Time", click on "Basic Algebra" and look in Chapter 5 for the section "5.01 Square Roots."  I also have a FREE video of me teaching this topic (from my younger days before I retired!)  Look on my Homepage for the link "Rapalje Videos in Living Color" and look in Basic Algebra for the one on Square Roots.  My explanations should be a LOT easier to understand than the traditional textbooks you are probably using.


Happy New Year!!  My Email address is rapaljer@seminolestate.edu if you need to contact me!!


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus