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6年级下学期的数学上海作业的19页最后一题思维训练1+1/2+1/6+1/12+1/20+1/30+1/42+1/56是

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/23 14:49:44
6年级下学期的数学上海作业的19页最后一题思维训练1+1/2+1/6+1/12+1/20+1/30+1/42+1/56是不是=2?
我数学不大好,嘻嘻
1+1/2+1/6+1/12+1/20+1/30+1/42+1/56
=1+[1/2+1/(2x3)+1/12+1/20+1/30+1/42+1/56]
=1+(2/3+1/12+1/20+1/30+1/42+1/56)
=1+[2/3+1/(3*4)+1/20+1/30+1/42+1/56]
=1+(3/4+1/20+1/30+1/42+1/56)
=1+[3/4+1/(4x5)+1/30+1/42+1/56]
=1+(4/5+1/30+1/42+1/56)
=1+[4/5+1/(5x6)+1/42+1/56]
=1+(5/6+1/42+1/56)
=1+[5/6+1/(6x7)+1/56]
=1+(6/7+1/56)
=1+[6/7+1/(7x8)]
=1+7/8
=15/8 即1又7/8