Rút gọn biểu thức:

Bài 3. Rút gọn biểu thức:

a/ x2(1x23−23x)(−x2−12x+53x3)x2(1x23−23x)(−x2−12x+53x3)

b/ (2x−1)⋅(2+3x)−0.5x(x−2,4)−112x2+2(2x−1)⋅(2+3x)−0.5x(x−2,4)−112x2+2

c/ (x+3)(43x2+12x−149)+3x+9(−49x2−2x+527)(x+3)(43x2+12x−149)+3x+9(−49x2−2x+527)

d/ (x+5)⋅(x−1)⋅(x−13−x2−25)