2⼀1*2*3+2⼀2*3*4+2⼀3*4*5+2⼀4*5*6+.....2⼀98*99*100简算 现在急需麻烦了

2024-12-04 02:08:08
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回答1:

2/1*2*3+2/2*3*4+2/3*4*5+2/4*5*6+.....2/98*99*100=(1/(1*2)-1/(2*3))+(1/(2*3)-1/(3*4))......+(1/(98*99)-1/(99*100))=1/2-1/(99*100)=(50*99-1)/(99*100)=4949/9900