3. Efectuați: a) (-25):(-5)-3-{-2-3.[-8:(-2)-(-2).(-1)]};

a)
(-25):(-5)-3×{-2-3×[-8:(-2)-(-2)×(-1)]}=
5-3×[-2-3×(4-2)]=
5-3×(-2-3×2)=
5-3×(-2-6)=
5-3×(-8)=
5+24=
=29
b)
(-25):(-5)-3×{-2-2×[(-12):2+3:(-1)]}=
5-3×[-2-2×(-6-3)]=
5-3×[-2-2×(-9)]=
5-3×(-2+18)=
5-3×16=
5-48=
=-43