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问题: 简算

1×1/3+3×1/5+5×1/7+……+99×101

要过程

解答:

1×1/3+3×1/5+5×1/7+……+99×101
=(1-1/3)÷2+(1/3-1/5)÷2+(1/5-1/7)÷2+……+(1/99-1/101)÷2
=[(1-1/3)+(1/3-1/5)+(1/5-1/7)+……+(1/99-1/101)]÷2
=(1-1/3+1/3-1/5+1/5-1/7+……+1/99-1/101)÷2
(中间互相抵消 )
=(1-1/101)÷2
=100/101÷2
=50/101