Let λ be a real number for which the system of linear equations x + y + x = 6, 4x + λy – λz = λ – 2, 3x + 2y – 4z = – 5 has infinitely many solutions. Then λ is a root of the quadratic equation:
(1) λ2 + λ – 6 = 0
(2) λ2 – λ – 6 = 0
(3) λ2 – 3λ – 4 = 0
(4) λ2 + 3λ – 4 = 0
