若丨2a+b+1丨+(a-1)²=0,则b-a=___

丨2a+b+1丨+(a-1)²=0
因为|2a+b+1|>=0 (a-1)^2>=0
所以|2a+b+1|=(a-1)^2=0
2a+b+1=a-1=0
b=-2a-1 a=1
b=-2*1-1=-3
b-a=-3-1=-4

2a+b+1=0,a-1=0,
a=1,b=-3
则b-a=-3-1=-4