已知(m²+n²)(m²+1+n²)=6,求m²+n²的值.​

问题描述:

已知(m²+n²)(m²+1+n²)=6,求m²+n²的值.​

设m²+n²=x,
x(x+1)=6
x=2,x=-3
∵m²+n²>0
∴m²+n²=2