Réponse :
C) (2x+3)^2 +(2x+3)(7x-2)
=4x^2+12x+9+14x^2+17x-6
=18x^2+29x+3
D) (2x+2)^2-9
=4x^2+8x+4-9
=4x^2+8x-5
E) (4x+1)^2-(3x-2)(4x+1)
= 16x^2+8x+1-12x^2+5x+3
= 4x^2+13x+4