Math Is Fun Forum

Hi,
I have a probelm with this:
if log(3)= x and log(5)= y, then log(45√15) =...??

I tried this: log(45)+log(√15) = log(3).(3).(5)+½log(3).(5)
then.. log(3)+log(3)+log(5)+½log(3)+log(5)
and that's all equal to.. x+x+y+½(x+y) = 2x+y+½(x+y) = 2x√x+y√y

but the real answer is ½(5x+2y)

anyone can help me? please..I really confuse...

Thank's..