Répondre :
1) a=x(5+3)=8x
b=x(3-8)=-5x
c=x(-4+15)=11x
d=x(-9-6)=-15x
2) a=12x-y+2
b=-6y+12
c=-8d+13
d=x^2+8
e=t^2-9t-7
f=a^2-a+4b
b=x(3-8)=-5x
c=x(-4+15)=11x
d=x(-9-6)=-15x
2) a=12x-y+2
b=-6y+12
c=-8d+13
d=x^2+8
e=t^2-9t-7
f=a^2-a+4b