Répondre :
A : -5x(-3)-5x(-4)=
15-(-20)=15+20=35
B : 17-6x[5+4x(-3)]=
17-6x(5+(-12))=
17-6x(5-12)=
17-6x(-7)=17-(-42)=17+42=59
C : 5/6 + 1/2x(7/6-4/9)=
5/6+1/2x(21/18-8/18)=
5/6+1/2x(13/18)=
5/6+13/36=30/36+13/36=43/36
15-(-20)=15+20=35
B : 17-6x[5+4x(-3)]=
17-6x(5+(-12))=
17-6x(5-12)=
17-6x(-7)=17-(-42)=17+42=59
C : 5/6 + 1/2x(7/6-4/9)=
5/6+1/2x(21/18-8/18)=
5/6+1/2x(13/18)=
5/6+13/36=30/36+13/36=43/36