1.1+1.91+1.991+1.9991+……+1.99999……991(100个9)=?怎么算```好麻烦`大家帮帮忙咯`
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1.1+1.91+1.991+1.9991+……+1.99999……991(100个9)=?
怎么算```好麻烦`大家帮帮忙咯`
在原式后加上0.9+0.09+0.009+0.0009+……+0.00……9(100个0)得:
2+2+2……+2(101个2)=2*101=202
从202中减去0.9999……9(101个9)得:201.00……001(100个1)
把它看成
(2-0.9)+(2-0.09)+....
所以就是
2x101-0.99999(101个9)=201.0000....1(101个0)
1.1+1.91+1.991+1.9991+……+1.99999……991(100个9)=
1.1+(1.91-1.2)+(1.991-1.2)+(1.9991-1.2)+……+(1.99999-1.2)……991(100个9)+100*1.2=
1.1-(0.09+0.009+0.009+……+0.000……009(100个0))+120
=1.1-(0.09999……9...
全部展开
1.1+1.91+1.991+1.9991+……+1.99999……991(100个9)=
1.1+(1.91-1.2)+(1.991-1.2)+(1.9991-1.2)+……+(1.99999-1.2)……991(100个9)+100*1.2=
1.1-(0.09+0.009+0.009+……+0.000……009(100个0))+120
=1.1-(0.09999……9999(100个9))+120
=1.0000……0000001(100个0)+120
=121.0000……0000001(100个0)
收起
1.1+1.91+1.991+1.9991+.+1.999...991(9个9)
计算:1.1+1.91+1.991+……+1.999……991(100个9).
1.1+1.91+1.991+1.9991+...+1.9999999991怎么简算
1.1+1.91+1.991+.+1.99.9991.99.9991是100个9
1.1+1.91+1.991+.+1.99(100个九)121:20之前要!要算术法!
1.1+1.91+1.991+.+1.{99.9}1 { }处为100个9
1+1.91+1.991+ …+1.9999991等于多少?
1.1+1.91+1.991+1.9991+……+1.99999……991(100个9)=?怎么算```好麻烦`大家帮帮忙咯`
1+1.91+1.991+...+1.99...991(100个9)的答案
1.1+1.91+1.991+1.99999……(100个九)1=多少这是一道数奥题,A.20.100……(100个0)1B.201.1000……(100个0)1C.2010.100000……(100个0)1
简算 5.97-3.81+1.91
1999+199.9+19.99+1.999 简算
1999+199.9+19.99+1.999+0.1999
1999+199.9+19.99+1.999=?
1999+199.9+19.99+1.999+0.1999
巧算 1.999+19.99+199.9+1999
1.999精确到0.01是多少
1.999精确到0.01是多少