poster et développer aider moi svp

Bonjour,

E = (4x + 5) (4x + 5) - (3x - 4)²
E = 16x² + 20x + 20x + 25 - (9x² - 24x + 16)
E = 16x² + 20x + 20x + 25 - 9x² + 24x - 16
E = 16x² - 9x² + 20x + 20x + 24x + 25 - 16
E = 7x² + 64x + 9

F = (5x - 4) (3x - 3) - 3 (2x - 1) (x + 3)
F = 15x² - 15x - 12x + 12 - 3 (2x² + 6x - x - 3)
F = 15x² - 15x - 12x + 12 - 6x² - 18x + 3x + 9
F = 15x² - 6x² - 15x - 12x - 18x + 3x + 12 + 9
F = 9x² - 42x + 21

H = 2 (4x - 3)² + 3 (2x + 3)²
H = 2 (16x² - 24x + 9) + 3 (4x² + 12x + 9)
H = 32x² - 48x + 18 + 12x² + 36x + 27
H = 32x² + 12x² - 48x + 36x + 18 + 27
H = 44x² - 12x + 45

I = (1/2x + 2)² - (2/3x - 3)²
I = 1/4x² + 4/2x + 4 - (4/9x² - 12/3x + 9)
I = 1/4x² + 2x + 4 - 4/9x² - 4x + 9
I = 1/4x² - 4/9x² + 2x - 4x + 9
I = 9/36x² - 16/36x² - 2x + 9
I = - 7/36x² - 2x + 9

K = 3/2x (4x - 2) + (3x + 3/4) (x - 4)
K = 12/2x² - 6/2x + 3x² - 12x + 3/4x - 12/4
K = 6x² - 3x + 3x² - 12x + 0,75x - 3
K = 6x² + 3x² - 3x - 12x + 0,75x - 3
K = 9x² + 14,25x - 3

L = (5x + 4) (5x - 4) + (5 - 4x) (5 + 4x)
L = 25x² - 20x + 20x - 16 + 25 + 20x - 20x - 16x²
L = 25x² - 16x² - 16 + 25
L = 9x² + 9

M = (6x - 4) (3 - 4x) - 5x (- 4 - 3x)
M = 18x - 24x² - 12 + 16x + 20x + 15x²
M = - 24x² + 15x² + 18x + 16x + 20x - 12
M = - 9x² + 54x - 12

N = 4 (3x - 5) (- 4x - 2) + 2 (- x + 4) (1 - 2x)
N = 4 (- 12x² - 6x + 20x + 10) + 2 (- x + 2x² + 4 - 8x)
N = - 48x² - 24x + 80x + 40 - 2x + 4x² + 8 - 16x
N = - 48x² + 4x² - 24x - 16x - 2x + 80x + 40 + 8
N = - 44x² + 38x + 48