Solve: x+y=7,2x−y=2x + y = 7, 2x - y = 2x+y=7,2x−y=2.
(3,4)(3, 4)(3,4)
(4,3)(4, 3)(4,3)
(2,5)(2, 5)(2,5)
(5,2)(5, 2)(5,2)