Question 47180
Remember this rule: log(a.b)=log(a)+log(b)

log2(8xy)=log2(8)+log2(x)+log2(y) 

Another rule:
log(a^b)=b.log(a)

log2(8xy)=log2(2^3)+log2(x)+log2(y) 
log2(8xy)=3.log2(2)+log2(x)+log2(y) 

Another rule: loga(a)=1

So the full expansion is:

log2(8xy)=3+log2(x)+log2(y)

I hope this helps,
Adam
P.S. please visit my website, it may be helpful to you. The address is www.geocities.com/quibowibbler