已知2m²-5m-1=0,(1/n)²+5/n-2=0,且m不等于n,求代数式n/m+m/n的值
问题描述：
已知2m²-5m-1=0,(1/n)²+5/n-2=0,且m不等于n,求代数式n/m+m/n的值
答
(1/n)²+5/n-2=0则2n²-5n-1=02m²-5m-1=0所以m和n是方程的2x²-5x-1=0根m+n=5/2,mn=-1/2则m²+n²=(m+n)²-2mn=29/4所以m/n=n/m=(m²+n²)/mn=-29/2