Rút gọn: (5x - 4).(2 + 3x) - 6x^2 - (3x - 5)^2

Bài 1: Rút gọn
a/ (5x - 4) (2 + 3x) - 6x^2 - (3x - 5)^2
b6x(2x + 1) + 3 (1- 4x^2)