bonsoir ,
A=(5x+2)² + (1+3x)²
A= 25x²+20x+4+1+6x+3x²
A= 28x²+26x+5
B= (2x - 3) (2x+3) - (1+x)²
B= 4x²+6x-6x-9 -x²-2x-1
B=3x² -2x-10
C= (3x + 2)² - (2x + 3)²
C= 9x² +12x +4 -4x² -12x -9
C=5x² - 5
D= (4-6x)² + (5 - 8x) (5+8x).
D= 16 -48x +36x² +25 +40x -40x -64x²
D= -28x² -48x +41