Répondre :
bonjour
a=3(2x-6)-(3-5x)=
6x-18-3+5x=
11x-21
b=(5-2y)-(3y+7)=
5-2y-3y-7=
-5y-2
c= 4(6+z)+(z-3)(2-z)=
24+4z+2z-z²-6+3z=
-z²+9z+18
d=(2t-5)(3t+2)-(t²+6)=
6t²+4t-15t-10-t²-6=
5t²-11t-16
a=3(2x-6)-(3-5x)=
6x-18-3+5x=
11x-21
b=(5-2y)-(3y+7)=
5-2y-3y-7=
-5y-2
c= 4(6+z)+(z-3)(2-z)=
24+4z+2z-z²-6+3z=
-z²+9z+18
d=(2t-5)(3t+2)-(t²+6)=
6t²+4t-15t-10-t²-6=
5t²-11t-16