已知點A(x,-4)與點B(3,y)關於x軸對稱,那麼x+y的值為___.

已知點A(x,-4)與點B(3,y)關於x軸對稱,那麼x+y的值為___.

∵點A(x,-4)與點B(3,y)關於x軸對稱,∴x=3,y=4,∴x+y=7,故答案為:7.