来自贾宝才的问题
【jieyixiayiyuansancifangchengn3-n=?dacuole,yinggaishi:n3-n=2,qiundezhi】
jieyixiayiyuansancifangcheng
n3-n=?
dacuole,yinggaishi:
n3-n=2,qiundezhi
1回答
2020-11-13 22:49
【jieyixiayiyuansancifangchengn3-n=?dacuole,yinggaishi:n3-n=2,qiundezhi】
jieyixiayiyuansancifangcheng
n3-n=?
dacuole,yinggaishi:
n3-n=2,qiundezhi
有个公式:n3-1=(n-1)*(n2+n+1)
所以原等式可转化为:n3-1=n-1
所以(n-1)*(n2+n+1)=n-1
所以n2+n+1=1
所以n2+n=0
所以n(n+1)=0
所以n=0或者-1
(检验略)