1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110=?
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110=?
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
42/1+56/1+72/1+90/1+110/1
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90简便运算怎么做
巧算:1/2+1/6+1/12+1/20+1/30+1/42+1/56=?
1/2+1/6+1/12+1/30+1/42
简算:1+12/6+36/12+80/20+150/30+252/42+392/56+576/72
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20 =
递等式计算:1/42+1/56+1/72+1/90+1/110
30/1+42/1+56/1=?
1又1/6+2又1/12+3又1/20+4又1/30+5又1/42+6又1/56+7又1/72 急
1+2/1-6/5+12/7-20/9+30/11-42/13+56/15-72/17=?