1) Ddévelopper
A= (4x^2+4x+1) - (2x^2+6x+1x+3)
A= (4x^2+4x+1) - (2x^2+7x+3)
A= 4x^2+4x+1 - 2x^2 -7x-3
A= 2x^2-3x-2
C= (3x^2-1x+21x-7) - 3x+1 + (x^2+4x-4x-16)
C= 3x^2 + 20x -7 - 3x+1 + x^2-16
C= 4x^2 + 20x - 23
2) Factoriser
D= (2x+1) (2x+1-x-3)
D= (2x+1) (1x-2)
