1/10x11+1/11x12+1/12x13+.....+1/99x100

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1/漏团10x11+1/11x12+1/12x13+.....+1/99x100
=1/10-1/11+1/11-1/12+1`/12-1/核神13+......+1/99-1/100
=1/返氏橘10-1/100
=9/100

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=100/10=10

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