m2+n2+mn+m-n=-1 2m²+2n²+2mn+2m-2n+2=0(m²+n²+2mn)+(m²+2m+1)+(n²-2n+1)=0(m+n)²+(m+1)²+(n-1)²=0m+1=0m=-1n-1=0n=11/m+1/n=-1+1=0