bonsoir aider moi. svp oour mon devoir merci

bonjour,

A = 7x(x²-y)

B = (2x-1)(2x+1-5x)
   = (2x-1)(-3x+1)

C = (x-3)(x-3+x+3)
   = (x-3)(2x)
   = 2x(x-3)

D = (3x-2)(3x-2-5+2x)
   = (3x-2)(5x-7)


2) 7x²-7xy
7(1/2)^3 - 7(1/2*1) =
7(1/8)-7/2 =
7/8 - 7/2 =
7/8-28/8 =

-21/8