问题 填空题
若|x-y+3|+
x+y-5
=0,则
x+2y
x-y
-(x-y)
=______.
答案

∵|x-y+3|+

x+y-5
=0,

∴可得|x-y+3|=0且

x+y-5
=0,

∴可求得:

x-y=-3
x+y=5

∴有

x=1
y=4

x+2y
x-y
-(x-y)

=

x+y+y
-3
-(-3)

=

5+4
-3
+3

=0,

故答案为0.

单项选择题
单项选择题