Question 588027
I have a problem with another like the first, but this makes no sense to me ata all.  The section says use the rule a√b*c√d=ac√bd.  Using this the problem is:
10√8*3√10= ?  
I tried several times using this rule above and I got the answer 30√80
to show how I came to that conclusion, I broke it down a step at a time as follows:  (10*3)√(8*10)= 30√80, however the book tells me the answer is 120√5. 
------------------
{{{30*sqrt(80) = 30*sqrt(16*5) = 30*sqrt(16)*sqrt(5)}}}
= {{{30*4*sqrt(5)}}}
= {{{120sqrt(5)}}}