1、10-2.4÷0.3x0.6
=10-8x0.6
=10-4.8
=5.2
2、12.5-7/9+7.5-11/9
=12.5+7.5-(7/9+11/9)
=20-2
=18
3、5/11x[(2/5+1/3)÷5/6]
=5/11x(2/5x6/5+1/3x6/5)
=5/11x(12/25+2/5)
=12/55+10/55
=22/55
=2/5