Question 83940
I assume this is the problem...
{{{x(sqrt(18))-3sqrt(8x^2)}}}
Start by pulling what you can out from under each square root sign. To see what can be pulled out, re-write as factors what is under each radical:
{{{x(sqrt(2*3*3))-3sqrt(2*2*2*x*x)}}}
Since you know that in general, sqrt(x^2)=x, you can start simplifying what is under the radicals by "pulling out" the proper terms, like this:
{{{3x(sqrt(2))-6x(sqrt(2))}}}
notice in the first term, I was able to put a 3 outside the radical, since I had 3*3 underneath. Likewise in the second term, I was able to pull out a 2x.
Simplifying, you get the final answer:
{{{highlight(-3x(sqrt(2)))}}}
Good Luck,
tutor_paul@yahoo.com