Hi, I need help in the following log questions:

a) Given that log(base b)(xy^3)=m and log(base b)(x^3y^2)=p. Express log(base b)(√xy) in terms of m and p.

b) Given 2^x=3y^2y=6^z, prove that 2xy-2yz-xz=0.

For a. I only know adding... but cannot get log(base b) (xy).. for b. I don't really know how to start....

Please help me in these questions, thanks.