Developper:
A= (2x+1)(3x-2)(-x+1)
A = (2x+1)(3x-2)(-x+1)
A = (6x²-4x+3x-2)(-x+1)
A = -6x^3+x²+2x+6x²-x-2
A = -6x^3+7x²+x-2
