Rút gọn các biểu thức sau đây: 5x^2.(3x^2 − 7x + 2)

1a) 5x2.(3x2−7x+2);5x2.(3x2−7x+2);                    

b) 23xy.(2x2y−3xy+y2)23xy.(2x2y−3xy+y2).

2a,(x+2)(x−2)−(x−3)(x+1)(x+2)(x−2)−(x−3)(x+1);
b,(2x+1)2+(3x−1)2+2(2x+1)(3x−1)(2x+1)2+(3x−1)2+2(2x+1)(3x−1) .