Solve: x+y=6,2x+y=9x + y = 6, 2x + y = 9x+y=6,2x+y=9.
(3,3)(3, 3)(3,3)
(2,4)(2, 4)(2,4)
(4,2)(4, 2)(4,2)
(1,5)(1, 5)(1,5)