Răspuns :
Nici acesta nu este bine rezolvat.
6+12+18+24+...+1200=
=6(1+2+3+200)=
=6*(201*200:2)=
=6*(201*100)=
=6*20100
=120600
6+12+18+24+...+1200=
=6(1+2+3+200)=
=6*(201*200:2)=
=6*(201*100)=
=6*20100
=120600