一道数奥题,(x+y-z)²+(y+z-4)=-|z+x-5|

(y+z-4)这里是丢了平方,还是()要变成绝对值符号?
(x+y-z)²=0
(y+z-4)=0
|z+x-5|=0
x+y=z
x+y+2z=9
z=3
y=1
x=2