Pouvais vous m’aider svp

Réponse :

Bonjour,

A = (7-3x)(9x-3)

A = 7*9x+7*(-3)-3x*9x-3x*(-3)

A = 63x-21-27x²+9x

A = -27x²+72x-21

B = (-2-3y)(4-8y)

B = -2*4-2*(-8y)-3y*4-3y*(-8y)

B = -8+16y-12y+24y²

B = 24y²+4y-8

C = (4a+6)(-3-5a)

C = 4a*(-3)+4a*(-5a)+6*(-3)+6*(-5a)

C = -12a-20a²-18-30a

C = -20a²-42a-18

D = (5z-7)(8z+2)

D = 5z*8z+5z*2-7*8z-7*2

D = 40z²+10z-56z-14

D = 40z²-46z-14