五年级数学题解答

显示全部楼层 · 2009-8-17 13:00:05

1/2+1/6+1/12+1/20+1/30+1/42+1/56=1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7+1/7*8=1/1-1/2+1/2-1/3+1/3-1/4+……+1/7-1/8=1-1/8=7/8

千问 · 2009-8-17 13:00:05

1/2+1/6+1/12+1/20+1/30+1/42+1/56=1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7+1/7*8=1/1-1/2+1/2-1/3+1/3-1/4+……+1/7-1/8=1-1/8=7/8 看不清

千问 · 2009-8-17 13:00:05

1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56=1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + 1/4 - 1/5 + 1/5 - 1/6 + 1/6 - 1/7 + 1/7 - 1/8=1 - 1/8=7/8

千问 · 2009-8-17 13:00:05

(1/2-1/3)+(1/3-1/4)......(1/7-1/8)=3/8

千问 · 2009-8-17 13:00:05

1/2+1/6+1/12+1/20+1/30+1/42+1/56=1/1×2+1/2×3+1/3×4+1/4×5+1/5×6+1/6×7+1/7×8=1/1-1/2+1/2-1/3+1/3-1/4+……+1/7-1/8=1-1/8=7/8