Solve: x−y=3,2x+y=9x - y = 3, 2x + y = 9x−y=3,2x+y=9.
(4,1)(4, 1)(4,1)
(3,0)(3, 0)(3,0)
(5,2)(5, 2)(5,2)
(2,−1)(2, -1)(2,−1)