=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7
=1-1/7
=6/7
=1/2+2/3+3/4+4/5+5/6+6/7
=3/6+4/6+5/6+3/4+4/5+6/7
=2+3/4+4/5+6/7
=2+15/20+16/20+6/7
=2+31/20+6/7
=2+217/140+120/140
=2+337/140
=280/140+337/140
=617/140
=4又57/140
=5/6+31/20+71/42
=35/42+(651+710)/420
=350/420+1361/420
=1711/420
=4又31/420
不知出此题目有何意义？
=1/2+2/3+3/4+4/5+5/6+6/7
=2+3/4+4/5+6/7
=2+337/140
=4又57/140
参考资料：小雨滴NNN
1x2分之1+2x3分之1+3x4分之1+4x5分之1+5x6分之1+6x7分之1 等几?
1x2分之1+2x3分之1+3x4分之1+4x5分之1+5x6分之1+6x7分 =1-1\/2+1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+1\/5-1\/6+1\/6-1\/7 =1-1\/7 =6\/7
1×2分之1加2×3分之1加3×4分之1加4×5分之1加5×6分之1加6×7分之...
1×2分之1加2×3分之1加3×4分之1加4×5分之1加5×6分之1加6×7分之1 =1-2分之1+2分之1-3分之1+3分之1-4分之1+4分之1-5分之1+5分之1 -6分之1+6分之1-7分之1 =1-7分之1 =7分之6 分数计算方法：分数乘整数的意义与整数乘法的意义相同，都是（求几个相同加数和的...
求高手帮助!1X2X3分之1+2X3X4分之1+3X4X5分之1+ ……+5X6X7分之1
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1x2\/1+2x3\/1+3x4\/1+4x5\/1+5x6\/1+6x7\/1+7x8\/1+8x9\/1+9x10\/1
1x2\/1+2x3\/1+3x4\/1+4x5\/1+5x6\/1+6x7\/1+7x8\/1+8x9\/1+9x10\/1 ＝1\/2+1\/6+1\/12+1\/20+1\/30+1\/42+1\/56+1\/72+1\/90 =(1-1\/2)+(1\/2-1\/3)+……+(1\/8-1\/9)+(1\/9-1\/10)=1-1\/10 =9\/10
简算题:1x2\/1+2x3\/1+3x4\/1+4x5\/1+5x6\/1+6x7\/1+7x8\/1+8x9\/1
估计楼主的题目出错了 是不是：1x1\/2+2x1\/3+3x1\/4+4x1\/5+5x1\/6+6x1\/7+7x1\/8+8x1\/9 ＝1\/2+2\/3+3\/4+4\/5+5\/6+6\/7+7\/8+8\/9 =33\/12+4\/5+6\/7+7\/8+8\/9 =22\/8+7\/8+4\/5+6\/7+8\/9 =29\/8+4\/5+6\/7+8\/9 =177\/40+6\/7+8\/9 1479\/280+8\/9 =14511\/152...
一乘二分之一+二乘三分之一加三乘四分之一加四乘五分之一+五×六分之...
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2分之1加6分之1加12分之1加20分之1加30分之1加42分之1加56分之1加72...
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1×2×3分之一+2×3×4分之一+4×5×6分之一+5×6×7分之一?
= 2\/3 + 10\/3 + 3\/2 + 30\/7 = 12\/3 + 3\/2 + 30\/7 = 4 + 3\/2 + 30\/7 = 56\/14 + 21\/14 + 60\/14 = 77\/14 + 60\/14 = 137\/14 = 9.785714286 ≈ 9.79 答：1×2×3分之一+2×3×4分之一+4×5×6分之一+5×6×7分之一等于137\/14，【即约等于9.79】...
1\/1x2+1\/2x3+1\/3x4+1\/4x5+1\/5x6+1\/6x7=?
原式=1-1\/2+1\/2-1\/3+…+1\/6-1\/7=1-1\/7=6\/7
一道小学五年级简便算法计算题五年级,在线等!!!急!十五分!
1\/1*2+1\/2*3+1\/3*4+1\/4*5+1\/5*6+1\/6*7 =1-1\/2+1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+1\/5-1\/6+1\/6-1\/7 =6\/7 因为1\/1*2=1-1\/2同理..
