在线等,谢谢!
∵P(m,1)与Q(2,n)关于x轴对称,∴m=2,1=-n,∴(m,n)=(2,-1)。∴m²+n²=2²+(-1)²=4+1=5//(x+5)²-(x-3)²[(x+5)-(x-3)]*[(x+5)+(x-3)]=8(2x+2)=16x+16