a)[(a-b)+c]+(a+c)=
=[(4-3)-11]+(4-11)=
=(1-11)+(-7)=
=-10-7=
=-17
b)[(a-b)+(c-a)]+(b-c)=
=[(4-3)+(-11-4)]+(3-4)=
=(1-15)-1=
=-14-1=
=-15
c) [(a+b)+c]+[(a-b)+c]=
=[(4+3)-11]+[(4-3)-11]=
=(7-11)+(1-11)=
=-6-10=
=-16
d)[(c-a)-b]-a=
=[(11-4)-3]-4=
=(7-3)-4=
=4-4=
=0