二分之一加六分之一加十二分之一加二十分之一等于多少

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=1/2+1/明余2*3+1/3*4+1/4*5
=1/2+1/2-1/3+1/3-1/4+1/激稿滚敬敏4-1/5
=1-1/5
=4/5

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1/2+1/悉亩塌6+1/12+1/20
=30/60+10/60+5/睁圆60+3/耐轮60
=48/60
=4/5

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=1/2+1/2-1/3+1/3-1/4+1/4-1/5
=1-1/5
=4/5

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=1/2+1/明余2*3+1/3*4+1/4*5
=1/2+1/2-1/3+1/3-1/4+1/激稿滚敬敏4-1/5
=1-1/5
=4/5

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