25.48-(9.4-4.52)
=25.48-9.4+4.52
=25.48+4.52-9.4
=30-(10-0.6)
=30-10+0.6
=20+0.6
=20.6
18.65-3.3×1.2
=18+13/20-33/10*6/5
=18+13/20-99/25
=18+13/20-3-24/25
=18-3+13/20-24/25
=15+(65-96)/100
=15-3/10
=15-0.3
=14.7