11 2 +21 6 +31 12 +…+91 90 +101 110
11 2 +21 6 +31 12 +…+91 90 +101 110
1-3/2+5/6-7/12+9/20-11/30+……19/90+21/110=
5/6-7/12+9/20-11/30+……-19/90+21/110 =
计算:1/2+5/6+11/12+19/20+……+89/90+109/110=
1/2+5/6-7/12+9/20-11/30.-19/90+21/110
1-3/2+5/6-7/12+9/20-11/30+.-19/90+21/110=?
1/2=1分之2 6/7+12/13+20/21+42/43+56/57+72/73+90/91+110/111+132
111+101+91+.+41+31+21=?
4-5/6+7/12-9/20+11/30-13/42+15/56-17/72+19/90-21/90-21/110+2
(+111)+(-101)+(91)+(-81)+...+(+31)+(-21)+(+11)+(-1)怎样巧算
7/6 + 13/12 +21/20+31/30+43/42+57/56+73/72+91/90 简便计算
7/6+13/12+21/20+30/31+42/43+57/56+73/72+91/90=?