Bonjour, Développer et réduire chaque expressions : A = 15x-(x+7)² B = x(x-1)-(x-2)² C = (x-2)(x+2)-(x+1)² Merci !

A = 15x - (x + 7)²

A = 15x - x² + 2 × 7 × x + 7²

A = 15x - x² + 14x + 49

A = -x² + 29x + 49

B = x (x - 1) - (x - 2)²

B = x² - x - ( x² - 2 × x × 2 - 2²)

B = x² - x - ( x² - 4x - 4)

B = x² - x - x² + 4x + 4

B = 3x + 4

C = (x - 2) (x + 2) - (x + 1)²

C = x² - 2² - (x² + 1 × x × 2 + 1²)

C = x² - 4 - (x² + 2x + 1)

C = x² - 4 - x² - 2x - 1

C = - 2x - 5