55;2
计算:1/55+2/55+3/55+.+54/55
简便计算:1/55+2/55+3/55+4/55+5/55+6/55+7/55+8/55+9/55+10/55-11/1
(1/55+2/55+3/55+~+10/55)-(11/155+12/155+~20/55)
55乘2等于
(10-4/55*1)+(9-4/55*2)+(8-4/55*3)+...+(2-4/55*9)+(1-4/55*10)
45^2+55^2+2*45*55简算
计算:55分之1+55分之2+55分之3.+55分之54.
急 (2 19:55:12)
55
1/55+2/55+3/55+.+10/155-11/155-12/155-.-20/155=?
1/55+2/55+3/55...+10/55-11/155-12/155-13/155-...-20/155
1+999+55+2+2+3