|x-2y+1|+(x+y-5)²=0,
|x-2y+1|=0,(x+y-5)²=0,
x-2y+1=0.1
x+y-5=0,.2
2式-1式得
3y-6=0
y=2
将y=2代入2式得
x+2-5=0
x-3=0
x=3
5x+4y
=5*3+4*2
=15+8
=23