巧算【789+789789+789789789】/【987+987987+987987987】
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/13 23:14:20
巧算【789+789789+789789789】/【987+987987+987987987】
1-2/3-2/9-2/27-2/81-2/243
1-2/3-2/9-2/27-2/81-2/243
【789+789789+789789789】/【987+987987+987987987】
=789*(1+1001+1001001)/[987*(1+1001+1001001)]
=789/987
=263/329
1-2/3-2/9-2/27-2/81-2/243
=1-(1-1/3)-(1/3-1/9)-(1/9-1/27)-(1/27-1/81)-(1/81-1/243)
=1-1+1/3-1/3+1/9-1/9+1/27-1/27+1/81+1/81-1/243
=1-1/243
=242/243
=789*(1+1001+1001001)/[987*(1+1001+1001001)]
=789/987
=263/329
1-2/3-2/9-2/27-2/81-2/243
=1-(1-1/3)-(1/3-1/9)-(1/9-1/27)-(1/27-1/81)-(1/81-1/243)
=1-1+1/3-1/3+1/9-1/9+1/27-1/27+1/81+1/81-1/243
=1-1/243
=242/243
321321*789-789789*321 要用简便方法.
123+321+456+654+789+987*123456789
789+987-(123+321)+543+345 ?
123+321+456+654+789+987=?
123+321+456+654+789+987=》?
987*654*321+123*456*789=?
今天是星期天,从今天算起,第987987……987(1998个987)天是星期几~
123+321+456+654+789+987等于多少
计算:123+456+789+987+654+321=______.
速算题1题123+321+456+654+789+987
123+321+234+432+345+543+...+789+987
123+123+123+123+321+456+654+789+987=多少?