Given that x^{2 }+ y^{2}= 11xy

Show that log [ (x-y)/3 ] = 0.5 (logx +logy)

Similarly,

Give that log [ (x-y)/3 ] = 0.5 (logx +logy)

Show that x^{2}+ y^{2}= 11xy

I really liked the log unit and understood it, but I was stumped on this question. It was for a test and it keeps bothering me.

What I did was completely wrong, but I will be able to understand it if someone shows the solution.