Tính: 2(x + 3)(2x - 4) + (4x + 1)(5 - x)

Tính:
a. 2 ( x + 3 ) ( 2x - 4 ) + ( 4x + 1 ) ( 5 - x )
b. ( 2x + 3 )^2 - 9
c. ( 4x - 1 )^2 + ( 3x + 1) ( 2 - 3x)