3x = 4x + 2y + 1 --> x + 2y = -1 ----(1)
2x - y + 5 = 13 --> 2x -y = 8 ----(2)
(2)*2 + (1) --> 5x = 15, x = 3
代入(1) --> 2y = -4, y = -2
x=3, y=-2