规律是：形如x + (a*b)/x=a+b的方程的两个实数解为x=a或x=b那么：方程x+(n²+n)/(x-3)=2n+4可化为：x-3 + (n²+n)/(x-3)=2n+1即：x-3+ n(n+1)/(x-3)=n+(n+1)则得：x-3=n或x-3=n+1解得：x=n+3或x=n+4...