(lg√27+lg8-3lg√10)/lg1.2
=(lg√3³+lg√4³-lg√10³)/lg1.2
=(3/2lg3+3/2lg4-3/2lg10)/lg1.2
=3/2(lg3+lg4-lg10)/lg1.2
=3/2lg(3*4÷10)/lg1.2
=3/2lg1.2/lg1.2
=3/2