若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)=

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若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)=

若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)=
若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)=

若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)=
设:
y=x+d
z=x+2d
(z-x)^2-4(x-y)(y-z)
=(x+2d-x)^2-4(x-x-d)(x+d-x-2d)
=4d^2-4(-d)(-d)
=4d^2-4d^2
=0

0,因为z-x=2(y-x)=2(z-y)