网友们,请帮我回答以下数学问题!!
8.1/0.45=
(0.65*57.4+0.574*35-57.4)/3=
0.666*0.7+0.222*0.9=
2150*3.8+215*51+2.15*1400+850*9.6+0.85*700=11.8*43-860*0.09=
1 1/2+2 1/6+3 1/12+4 1/20+5 1/30+6 1/42=
注:1 1/2为一又二分之一,以此类推,全要过程!!!!!!!!!!! 展开
推荐于2016-02-22 · 知道合伙人教育行家
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8.1/0.45
=8.1÷(0.9×0.5)
=8.1÷0.9÷0.5
=9÷0.5
=18
(0.65*57.4+0.574*35-57.4)/3
=(0.65*57.4+57.4*0.35-57.4*1)/3
=57.4*(0.65+0.35-1)/3
=57.4*0/3
=0
0.666*0.7+0.222*0.9
=0.222*3*0.7+0.222*0.9
=0.222*(2.1+0.9)
=0.222*3
=0.666
2150*3.8+215*51+2.15*1400+850*9.6+0.85*700
=215*38+215*51+215*14+85*96+85*7
=215x(38+51+14)+85x(96+7)
=215x103+85x103
=(215+85)x103
=200x103
=20600
11.8*43-860*0.09
=11.8x43-43x20x0.09
=43x(11.8-1.8)
=43x10
=430
1 1/2+2 1/6+3 1/12+4 1/20+5 1/30+6 1/42
=(1+2+3+4+5+6)+(1/2+1/2x3+1/3x4+……+1/6x7)
=21+(1/2+1/2-1/3+1/3-1/4+……+1/6-1/7)
=21+(1/2+1/2-1/7)
=21+6/7
=21又7分之6
满意请采纳。
你在讲什么?我完全不知道!你发错了吧!!!!!!
57.4(0.65+0.35-1)/3=57.4*0/3=0
2150(3.8+5.1+1.4)+850(9.6+0.7)=2150*10.3+850*10.3=10.3*(2150+850)=10.3*3000=30900
(1+2+3+4+5+6)+1/2+1/6+1/12+1/20+1/30+1/42=21+(6+2+1)/12+(3+2)/60+1/42=21+9/12+1/12+1/42=21+10/12+1/42=21+70/84+2/84=21+72/84=21+6/7