规定X@y=Xx(X+1)x(X+2)x.x(X+y-1),如2@4=2x3x4x5已知n+1/n@3=1/575,求自然数n
人气：421 ℃ 时间：2019-11-14 06:29:15
解答
题目是这样的：（n+1）/【n@3】=（n+1） /【 n *（n+1）*（n+2）】=1/575
所以575*（n+1）=n *（n+1）*（n+2）
化简得n^3+3n^2-573n-575=0
解得n=23
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