Помогите решить логарифмы,пожалуйста досконально!пункт в)г)

Log135/log3-log5/log3=log135/(1/log15)-log5/(1/log405)=
=log135*log15-log5*log405=log(27*5)*log(3*5)-log5*log(81*5)=
=(log27+log5)(log3+log5)-log5*(log81+log5)=
=(3+log5)(1+log5)-log5*(4+log5)=
=3+log5+3*log5+(log5)-4*log5-(log5)=
=3+4log5-4log5=3;
[(3+log27)/(3-log27)]*log16=[(3+3log3)/(3-3log3)]*log16=
=[3(1+log3)/3(1-log3)]*4*log2=(log12+log3)/(log12-log3)*log16=
=(log36/log4)*log16=
=[(log36/log12)/(log4/log12)]*log16/log6=
=(log36/log4)*log2/log6=(2log6/2log2)*(4*log2/log6)=
=log6*4/log6=4;