根据六分之一等于二乘三分之一等于二分之一减三分之一来写
第1个回答 2010-09-18
1/42=(7-6)/(7*6)
=7/(7*6)-6/(7*6)
=1/6-1/7
同理可得:原式=(1/6-1/7)+(1/7-1/8)+…+(1/10-1/11) (化简)
=1/6-1/7+1/7-1/8+…+1/10-1/11 (去括号)
=1/6-1/11 (抵消)
=5/66本回答被网友采纳
=7/(7*6)-6/(7*6)
=1/6-1/7
同理可得:原式=(1/6-1/7)+(1/7-1/8)+…+(1/10-1/11) (化简)
=1/6-1/7+1/7-1/8+…+1/10-1/11 (去括号)
=1/6-1/11 (抵消)
=5/66本回答被网友采纳
第2个回答 2010-09-18
1/42+1/56+1/72+1/81+1/90+1/110
=1/(6*7)+1/(7*8)+1/(8*9)+1/(9*10)+1/(10*11)
=1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10+1/10-1/11
=1/6-1/11
=5/66
=1/(6*7)+1/(7*8)+1/(8*9)+1/(9*10)+1/(10*11)
=1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10+1/10-1/11
=1/6-1/11
=5/66
第3个回答 2010-09-19
saF
第4个回答 2010-09-24
太夸张了