1/1x2+1/2x3+1/3x4+……+1/8x9+1/9x10=
你们前面都是1-*** 哪请问，1哪儿来的？？
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10
=1-1/2+1/2-1/3+1/3-1/4+....+1/8-1/9+1/9-1/10
=1-1/10
=9/10
1/1x2=1/2=1-(1/2)
1/2x3=1/6=1/2 - 1/3
....
1/9x10=1/9-1/10
=1-1/2+1/2-1/3+1/3-1/4+....+1/8-1/9+1/9-1/10
=1-1/10
=9/10
1/1x2=1/2=1-(1/2)
1/2x3=1/6=1/2 - 1/3
....
1/9x10=1/9-1/10
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第1个回答 2011-10-10
1/1x2+1/2x3+1/3x4+……+1/8x9+1/9x10
=1-1/2+1/2-1/3+....+1/9-1/10
=1-1/10
=9/10
=1-1/2+1/2-1/3+....+1/9-1/10
=1-1/10
=9/10
第2个回答 2011-10-10
1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8+1/8x9+1/9x10
=1-1/2+1/2-1/3+.....+1/9-1/10
=1-1/10
=9/10
=1-1/2+1/2-1/3+.....+1/9-1/10
=1-1/10
=9/10
