Réponse :

salut

C= -3x+5-7x+2x-6x-6

  = -3x-7x+2x-6x+5-6

 = -14x-1

D= 4x-5+6x²+4-2x²-x+x²-7x

 = 6x²-2x²+x²+4x-x-7x-5+4

 = 5x²-4x-1

K= 5x-(2x-3)

 = 5x-2x+3

 =3x+3

L=3x²-(4x²-x+5)

 = 3x²-4x²+x-5

 = -x²+x-5

O= (6a+8)-(4a+2)

  = 6a+8-4a-2

  = 2a+6

M=4+6x-(-2x+7)

  = 4+6x+2x-7

  =8x-3

N=-5x-(-5x²+x-1)

  = -5x+5x²-x+1

  = 5x²-6x+1

P= (7b-2)+(3b-5)

 = 7b-2+3b-5

 = 10b-7

Explications étape par étape