15Twilight 15Twilight 27-03-2015 Mathematics Answered Solve the following system of equations? x + 3y - z = 2 x - 2y + 3z = 7 x + 2y - 5z = -21 a)(2, 3, 5) b)(-2, 3, 5) c)(2, -3, 5) d)(2, -3, 5)