计算:(1/50-1)*(1/49-1)*(1/48-1)*...*(1/4-1)*(1/3-1)

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计算:(1/50-1)*(1/49-1)*(1/48-1)*...*(1/4-1)*(1/3-1)
计算:(1/50-1)*(1/49-1)*(1/48-1)*...*(1/4-1)*(1/3-1)

计算:(1/50-1)*(1/49-1)*(1/48-1)*...*(1/4-1)*(1/3-1)
(1/50-1)*(1/49-1)*(1/48-1)*...*(1/4-1)*(1/3-1)
=(-49/50)*(-48/49)*(-47/48)*……*(-2/3)
共有48个负因数,所以结果是正数,前一个分数的分子可以与后一个分数的分母约去
=2/50
=1/25

(1/50-1)(1/49-1)(1/48-1)…(1/3-1)
=(-49/50)(-48/49)(-47/48)...(-2/3)
=2/50
=1/25
共有48项,所以是正数,中间数都交叉约去了