（1）1.18×2.58+0.5+1.42×1.18

=1.18×（2.58+1.42）+0.5

=1.18×4+0.5

=4.72+0.5

=5.22；

（2）（21.85-17.5）×（0.45÷0.9）

=4.35×0.5

=2.175；

（3）1.75×（0.1÷0.2）-0.18÷0.9

=1.75×0.5-0.2

=0.875-0.2

=0.675；

（4）93.6÷[（54.8+45.2）×（6-5.46）]

=93.6÷[100×0.54]

=93.6÷54

=