Find the value of a and b for which the equation x + ay + z = 3, x² + y² + z = b, x⁵ + y³ + z = 9 are consistent. When will these equations have unique solutions?
(a) a = 2, b = 19
(b) a = -2, b = -19
(c) a = 2, b = -19
(d) a = -2, b = 19