<●1. =-6: <●4. =+428;
<●2. =-6; <●5. = >7. =
<●3. =-39; <●6. =
●1.(+3-12+7)•(-8+6+5)=(-9+7)•(-2+5)=(-2)•3=-6;
●2.(+5-11+3)•(+4-8+6)=(-6+3)•(-4+6)=(-3)•2=-6;
●3.+3•[+3•(-8+6-4)+15]+21=3•[3•(-2-4)+15]+21=3•[3•(-6)+15]=3•(-18)+15=-54+15=-39;
●4.-3•{-8-3•[-2•(+4-7+5-3)•(-6+4-3)+6]}=
=-3•{-8-3•[-2•(8-3)•(-2-3)+6]}=
=-3•[-8-3•(-2•5•-5+6)]=
=-3•[-8-3•(-10•-5+6)]=
=-3•[-8-3•(50+6)=
=-3•(-8-3•56)=
=-3•(-8-168)=
=-3•(-176)=
=+428;
5. Le fac mâine că îmi este foarte somn