Rewrite as: logx(x+2)=log(x+6), so x(x+2)=x+6, and x^2+2x=x+6. x^2+x-6=0, factorised to (x+3)(x-2). Therefore x=-3 or 2. We have to reject -3 because we can't evaluate log-1. Putting x=2 in the original equation and we get log4+log2=log8, which is true.