Question

6+12+18+...+12000am nevoie de ajutor

Answer 1

6+12+18+...+12000=
6x(1+2+3+...+2000)=
6x2000x2001:2=
6x2001000=12006000

Answer 2

prima data aflam cate numere sunt in sir
(12000-6):6+1=11994:6+1=1999+1=2000 de numere
acum aflam suma sirului
(12000+6) * 2000 : 2 =
12006 * 1000=
12006000