题目应是 已知m、n互为相反数,且满足（m+4)²-(n+4)²+16=0,求m²+n²-2mn的值已知m、n互为相反数m+n=0（m+4)²-(n+4)²+16=0m²+8m+16-n²-8n-16+16=0m²-n²+8m-8n+16=0(...