题目内容：

如果,4（x-y）（y-z）=（x-z）^2,求x+z与y之间的关系

优质解答

4(x-y)(y-z)=(x-z)^2
4(x-y)(y-z)=[(x-y)+(y-z)]^2
4(x-y)(y-z)=(x-y)^2+2(x-y)(y-z)+(y-z)^2
(x-y)^2-2(x-y)(y-z)+(y-z)^2=0
[(x-y)-(y-z)]^2=0
x-y-y+z=0
所以x+z=2y