lig3 18/3+log3 12
=log_(3) (18)/(3+log_(3)12)= =log_(3)18/(log_(3)27+log_(3)12)= =log_(3)18/log_(3)(27*12)= =log_(3)18/log_(3)(324)= =log_(3)18/log_(3)(18^2)=log_(3)18/2log_(3)18=1/2