40.86-(2.75+0.86)
可以这样解:
=40+0.86-2.75-0.86
=40-2.75
=40-(3-0.25)
=40-3+0.25
=37+0.25
=37.25
40.86-(2.75+0.86)
=40.86-2.75-0.86
=40.86-0.86-(3-0.25)
=40-3+0.25
=37.25
40.86-(2.75+0.86)
=40.86-0.86-2.75
=40-2.75
=37.25
40.86-(2.75+0.86)=40.86-20.75-0.86=40.86-0.86-2075=40-20.75=19.25。
40.86_(2.75+0.86)
=40+0.86-2.75-0.86
=40-2.75
=40-(3-0.25)
=40-3+0.25
=37.25