记n!=n(n-1)(n-2).……3.2.1,则2⼀3!+3⼀4!+4⼀5!+……+99⼀100!为

2026年09月24日 13:02
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解答:
2/3!+3/4!+4/5!+……+99/100!
= (3-1)/3!+(4-1)/4!+(5-1)/5!+……+(100-1)/100!
=3/3!-1/3!+4/4!-1/4!+5/5!-1/5!+.........+100/100!-1/100!
=1/2!-1/3!+1/3!-1/4!+1/4!-1/5!+........+1/99!-1/100!
=1/2!-1/100!
=1/2-1/100!