5x - 6y = -38 . . . . . (1)
3x + 4y = 0 . . . . . (2)
(1) x 3 => 15x - 18y = -114 . . . . . (3)
(2) x 5 => 15x + 20y = 0 . . . . . . (4)
(3) - (4) => -38y = -114 => y = -114/-38 = 3
From (2), 3x + 4(3) = 0 => 3x + 12 = 0 => 3x = -12 => x = -12/3 = -4