Răspuns :
Răspuns:
5 + 10 + 15 + 20 + ... + 120 =
5(1+2+3+...+24)=
5·[(24·(24+1)]/2=
5·300=
1500
5(1+2+3+4+....+24) = 5[(1+24)*24]/2 = 5[25*12] = 5*300 = 1500
Răspuns:
5 + 10 + 15 + 20 + ... + 120 =
5(1+2+3+...+24)=
5·[(24·(24+1)]/2=
5·300=
1500
5(1+2+3+4+....+24) = 5[(1+24)*24]/2 = 5[25*12] = 5*300 = 1500