Question

若直线y=-x+m与直线y=2x+n的交点坐标为（-5,1）,则代数式m^2-2mn+n^2的值为

Answer 1

x=-5 y=1分别代入两直线方程：

1=5+m m=-4

1=2(-5)+n n=11

m^2-2mn+n^2

=(n-m)^2

=(11+4)^2

=15^2

=225