Răspuns :
1) 2-(-17-6-3)-56=2-(-26)-56=2+26-56=28-56=28
2)-14+[-6-3+(-6-5)]=-14+(-6-3-11)=-14-20=-34
3)-13+[-17-(-31+19+3)]=-13+(-17+9)=-13-8=-21
2-[-17+(2-8)-3]+(-17-39)=
=2-[-17+(-6)-3]+56
=2-[23-3]+56
=2-20+56
=-18+56
=38
-14+{-6-3+[-6+(-5)]}=
=-14+{-6-3+11}
=-14+{9+11}
=-14+20
=6
-13+{-17-[-31+19-(-3)]}=
=-13+{-17-[-31+22]}
=-13+{-17-9}
=-13+26
=13
=2-[-17+(-6)-3]+56
=2-[23-3]+56
=2-20+56
=-18+56
=38
-14+{-6-3+[-6+(-5)]}=
=-14+{-6-3+11}
=-14+{9+11}
=-14+20
=6
-13+{-17-[-31+19-(-3)]}=
=-13+{-17-[-31+22]}
=-13+{-17-9}
=-13+26
=13