m是奇数,且m>=3=>m可以用表达式2n-1,n>=2=>m²-1 = (2n-1)²-1=>m²-1 = 4n²-4n+1-1=>m²-1 = 4n²-4n=>m²-1 = 4n(n-1)=>m²-1 = 4*奇数*偶数由于n>=2,则4*奇数*偶数必然能被8整除=>m²-1必然能被8整除=>m(m²-1)必然也能被8整除