Rút gọn biểu thức: 2x(x - 4)^2 - (x + 5)(x - 2)(x + 2) + 2(x + 5)^2 - (x - 1)^2
Rút gọn biểu thức: 2x(x – 4)2 – (x + 5)(x – 2)(x + 2) + 2(x + 5)2 – (x – 1)2.
2x(x – 4)2 – (x + 5)(x – 2)(x + 2) + 2(x + 5)2 – (x – 1)2
= 2x(x2 – 8x + 16) – (x + 5)(x2 – 4) + 2(x2 + 10x + 25) – (x2 – 2x + 1)
= 2x3 – 16x2 + 32x – x3 + 4x – 5x2 + 20 + 2x2 + 20x + 50 – x2 + 2x – 1
= x3 – 20x2 + 58x + 69.