1、1/2,1/5,1/5,2/25,2/125,() 2、1/80*81+1/81*82+……+1/99*100=()
1、1/2,1/5,1/5,2/25,2/125,() 2、1/80*81+1/81*82+……+1/99*100=()
一个数学题:1/(80*81)+1/(81*82)+……+1/(99*100)
1/80*81 1/81*82 . 1/99*100()
1-1/2+1/3-1/4+1/5-1/6…+1/99-1/100)/(1/51+1/52+1/53+…+1/99+1/
1/(1*2)+1/(2*3)+1*(3*4)+1/(4*5)……1/(98*99)+1/(99+100)=?
1/1×2+1/2×3+1/3×4+1/4×5+……+1/98×99+1/99×100=()简算
1、(1+2/5)(1-2/5)(1+2/7)(1-2/7)*……*(1+2/99)(1-2/99)
(-1)+(+2)+(-3)+(+4)+(-5)+……+(-99)+(+100)=?
1/(1*3)+1/(2*4)+1/(3*5)+……+1/(98*100)+1/(99*101)=?
简算 1,728×98 2,502×73 3,67×81+34×81-81 4,275+99×275 5,125×84
1/(1+2) + 1/(1+2+3) + 1/(1+2+3+4)……+1/(1+2+3+4+……+99+100)=(
数学运算1/(80*81) + 1/(81*82) + .+1/(99*100)=?