Urgent!!! Développer puis réduire: 7x 2 - (2x + 1)(3 - 4x)(x - 2)3 - (3x + 1)(2x + 2)

7x^2 - (2x + 1)(3 - 4x)(x - 2)^3 - (3x + 1)(2x + 2)
7x^2 - (6x - 8x^2 + 3 - 4x)(x - 2)^3 - (6x^2 + 6x + 2x + 2)
7x^2 - (-8x^2 + 2x + 3)(x - 2)^3 - 6x^2 - 8x - 2
x^2 - 8x - 2 - (-8x^2 + 2x + 3)(x - 2)(x - 2)^2
x^2 - 8x - 2 + (8x^2 - 2x - 3)(x - 2)(x^2 - 4x + 4)
x^2 - 8x - 2 + (8x^3 - 16x^2 - 2x^2 + 4x - 3x + 6)(x^2 - 4x + 4)

x^2 - 8x - 2 + (8x^3 - 18x^2 + x + 6)(x^2 - 4x + 4)

x^2 - 8x - 2 + 8x^5 - 32x^4 + 32x^3 - 18x^4 + 72x^3 + 72x^2 + x^3 - 4x^2 + 4x + 6x^2 - 24x + 24

8x^5 - 50x^4 + 105x^3 + 75x^2 - 28x + 22