Question

若x,y,z为实数,且满足(x-z)(x-z)-4(x-y)(y-z)=0则哪个成立 A x+y+z=0 B x+y-2

Answer 1

(x-z)(x-z)-4(x-y)(y-z)=x^2+2xz+z^2-4xy+4y^2-4yz=(x+z-2y)^2=0.

所以,x+z-2y=0,选D.