87*五分之二+12除以二分之五+40%
=87x0.4+12x0.4+0.4
=(87+12+1)x0.4
=100x0.4
=40
(一又七分之四+0.75+二又七分之三+ 一又四分之三)÷(3-一又三分支一)
=(1又4/7+2又3/7+0.75+1.75)÷5/3
=(4+2.5)x0.6
=6.5x0.6
=3.9
如果本题有什么不明白可以追问,
87*五分之二+12除以二分之五+40%
=87x0.4+12x0.4+0.4
=(87+12+1)x0.4
=100x0.4
=40
(一又七分之四+0.75+二又七分之三+ 一又四分之三)÷(3-一又三分支一)
=(1又4/7+2又3/7+0.75+1.75)÷5/3
=(4+2.5)x0.6
=6.5x0.6
=3.9
如果本题有什么不明白可以追问,