2m^2-5m-1=0n^2+5n-2=0 两边同时除以n^21+5/n-2/n^2=0即2(1/n)^2-5*(1/n)-1=0那么m,1/n是方程 2x^2-5x-1=0的根,若m≠1/n那么m+1/n=5/2,m/n=-1/2∴(mn+m+1)/n=m+m/n+1/n=5/2-1/2=2m=1/n时,mn=1 2m^2-5m-1=0(mn+m+1)/n=(2+m)*m=m^2+2m解方程求出m的值即可