Bonjour les 3 derniers s’il vous plaît merci

Bonjour

L = (1 - 2n)² - (3n + 2) (3n - 2)

L = 1 - 4n + 4n² - (9n² - 4)

L = 1 - 4n + 4n² - 9n² + 4

L = - 5n² - 4n + 5

M = 3 (4x + 1) (x + 1) + (2 - x/2)²

M = 3 (4x² + 4x + x + 1) + 4 - 4x/4 + x²/4

M = 12x² + 12x + 3x + 3 + 4 - 4x/4 + x²/4

M = 48x²/4 + x²/4 + 12x + 3x - 2x + 7

M = 49x²/4 + 13x + 7

N = (n + 5) (n - 5) - 1/3 (1 - 3n)²

N = n² - 25 - 1/3 (1 - 6n + 9n²)

N = n² - 25 - 1/3 + 6/3n - 9/3n²

N = n² - 25 - 1/3 + 2n - 3n²

N = - 2n² + 2n - 75 /3 - 1/3

N = - 2n² + 2n - 76/3