Rút gọn: ( 6x + 1)² + (6x - 1)² - 2(1 + 6x)(6x - 1)

1. ( 6x+1)²+(6x-1)²-2(1+6x)(6x-1)
2. x (2x²-3)-x²(5x+1)+x²
3.3x(x-2)-5x(1-x)-8(x²-3)