Tìm x, biết: (x - 2)^2 - (x - 3)(x + 3) = 6

Tìm x, biết:
a) (x – 2)^2 – (x – 3)(x + 3) = 6.
b) 4(x – 3)^2 – (2x – 1)(2x + 1) = 10
c) (x – 4)^2 – (x – 2)(x + 2) = 6
d) 9 (x + 1)2 – (3x – 2)(3x + 2) = 10