已知|x-2y+11+1x+y-5|=0项X-Y的值

已知|x-2y+11+1x+y-5|=0项X-Y的值
已知|x-2y+11+1x+y-5|=0项X-Y的值

已知|x-2y+11+1x+y-5|=0项X-Y的值
| x-2y+1 | + | x+y-5 | = 0
x-2y+1 =0,x+y-5 = 0
X=3,Y=2
X-Y = 3-2 = 1

出错了把，应该是+1，不是+1x把
=x-2y+11+x+y-5
=x-y+7
x-y+7=0
x-y=-7

|x-2y+1|+|x+y-5|=0
则x-2y+1=0且x+y-5=0
y=2,x=3
X-Y的值为1