Au secours !!! je dois faire l'exercice 5 et 6 HELPPPPPP!!!

5)
A = (2x + 1)² + 2 (x - 4)
A = 4x²+ 4x + 1 + 2x - 8
A = 4x² + 6x - 7

B = (3x - 2)² - (4x + 2)
B = 9x² - 12x + 4 - 4x + 2
B = 9x² - 16x + 6

6)
C = (2x + 3)² - (3x - 4)²
C = 4x² + 12x + 9 - (9x² - 24x + 16)
C = 4x² + 12x + 9 - 9x² + 24x - 16
C = - 5x² + 36x - 7

D = (x - 5)² + (1- 4x)²
D = x²  - 10x + 25 + (1 - 8x + 16x²)
D = x² - 10x + 25 + 1 - 8x + 16x²
D = 17x² - 18x + 26

E = (4x - 3)² - (2x + 1) (3x - 2)
E = 16x² - 24x + 9 + 6x² - 4x + 3x - 2
E = 22x² - 25x + 7