问题 填空题 若(y+2)2+x+y-1=0,则x-y的值为______. 答案 ∵(y+2)2+x+y-1=0,∴y+2=0x+y-1=0,解得:x=3,y=-2,∴x-y=3-(-2)=5.故答案为5.