When (ax³ + x² + 2x + b) is divided by (x + 1), the remainder is 20. When it is divided by (x - 1), the remainder is 10. Find the values of (a) and (b).

a) (a = 3, b = 12)
b) (a = 2, b = 10)
c) (a = 1, b = 8)
d) (a = 4, b = 16)