1/1×2+1/2×3+1/3×4+1/4×5+……+1/98×99+1/99×100=()简算
1/1×2+1/2×3+1/3×4+1/4×5+……+1/98×99+1/99×100=()简算
1/(1*2)+1/(2*3)+1*(3*4)+1/(4*5)……1/(98*99)+1/(99+100)=?
1×2×1/3+2×3×1/4+……98×99×1/100=?
1+2+3+4+5+6…………+98+99+100=?
(1+2/3+2+3/4+3+4/5+……+97+98/99+98+99/100)/(3+1/3+5+2/4+7+3/5
奥数题1/1×2×3+1/2×3×4+……+1/98×99×100
1/(1*3)+1/(2*4)+1/(3*5)+……+1/(98*100)+1/(99*101)=?
(-1)+(+2)+(-3)+(+4)+(-5)+……+(-99)+(+100)=?
100+99-98-97+96+95-94-93+……+4+3-2-1简算
1×3+2×4+3×5……+97×99+98×100=
1+2+3+4+5+6+7+8+9+…………+99+100简算
计算:1/1*2+1/2*3+1/3*4+1/4*5+……+1/98*99+1/99*100