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问题: 单位分数的分拆

在1/2,1/3,1/4,1/6,1/12,1/15,1/20中,哪几个单位分数之和为1?

因为1=1/2+1/3+1/6,而1/3=1/( )+/( ) 1/6=1/( )+1/( )
用两个单位分数来替换1/3,得到:1=1/( )+1/( )+1/( )+1/( )
用两个单位分数来替换1/6,得妻:1=1/( )+1/( )+1/( )+1/( )


1/3=1/( )+1/( )+1/( ) 因为1=1/( )+1/( )+/( )而1/3*1=1/3*{1/( )+1/( )+1/( )}所以1/3=1/( )+1/( )+1/( )


把1/8,1/12分别拆为三个单位分数之和。(分母在100以内)
(1)分母8的因数有(  )
1/8=( )+( )+( )/8*{( )+( )+( )}=
1/8=( )+( )+( )/8*{( )+( )+( )}=
(2)分母12的因数有(   )
1/12=( )+( )+( )/12*{( )+( )+( )}=
1/12=( )+( )+( )/12*{( )+( )+( )}=

解答:

在1/2,1/3,1/4,1/6,1/12,1/15,1/20中,哪几个单位分数之和为1? 你写的题干是不是还少个数啊(1/60或1/30)?

因为1=1/2+1/3+1/6,而1/3=1/(4 )+1/( 12) 1/6=1/12+1/15+1/60=1/12+1/20+1/30 =1/15+1/20+1/20
用两个单位分数来替换1/3,得到:1=1/(2 )+1/( 4)+1/( 12)+1/( 6)
用两个单位分数来替换1/6,得妻:1=1/( )+1/( )+1/( )+1/( )


1/3=1/( )+1/( )+1/( ) 因为1=1/( 2)+1/( 3)+/( 6)而1/3*1=1/3*{1/( 2)+1/(3 )+1/(6 )}所以1/3=1/( 6)+1/(9 )+1/(18 )