Question

1+2又1/6+3又1/12，加上四又1/20，加上五又1/30，加上六又1/42，简便计算。

Answer 1

原式＝21又14分之5

Answer 2

1+2又1/6+3又1/12+4又1/20+5又1/30
=1+2+3+4+5+(1/6+1/12)+(1/20+1/30)
=15+（2/12+1/12）+（3/60+2/60）
=15+3/12+5/60
=15+3/12+1/12
=15+4/12
=15又1/3

追答

拉了个1/42，改:
1+2又1/6+3又1/12+4又1/20+5又1/30+6又1/42
=(1+2+3+4+5+6)+（1/6+1/12）+（1/20+1/30）+1/42
=21+3/12+5/60+1/42
=21+3/12+1/12+1/42
=21+1/3+1/42
=21+14/42+1/42
=21+15/42
=21又5/14

Answer 3

家里康复扣抠安全喽吼喽咯一色儿呢路特

Answer 4

原式=(1+2+3+4+5+6)+(1/6)+(1/12)+(1/20)+(1/30)+(1/42)

=21+[(1/2)-(1/3)]+[(1/3)-(1/4)]+……+[(1/6)-(1/7)]

=21+(1/2)-(1/7)

=21+(5/14)

=21又5/14