bjr

A = 6² - (5x)² = 36 - 25x² = -25x² + 36

puisque (a+b) (a-b) = a² - b²

B = (x+1) (5-x - 2(4x+3)) = (x+1) (5 - x - 8x - 6) = (x+1) (-9x-1)

C = (8x)² - 10² = (8x+10) (8x-10)

D = 36 - (1-2x)²

si x = -1

D = 36 - (1 - 2*(-1))² = 36 - (1 +2)² = 36 - 3² = 36 - 9 = 27

D = 36 - (1 - 4x + 4x²) = -4x² + 4x + 35

D = 6² - (1-2x)² = (6 + 1-2x) (6-(1-2x)) = (-2x+7) (2x + 5)

(4x-5) (18+3x) = 0

soit 4x-5=0 => x =5/4

soit 18+3x =0 => x = -6