Which of the following integer pairs (x,y)(x, y)(x,y) are solutions to the equation x+y=7x + y = 7x+y=7?
(3,4)(3, 4)(3,4)
(5,2)(5, 2)(5,2)
(8,−1)(8, -1)(8,−1)
(0,8)(0, 8)(0,8)