Question

2+4+6+.........+400
---------------------------
3+6+9+.........+600

Answer 1

2+4+6+.........+400=
2(1+2+3+.....+200)=
Se foloseste formula lui Gauss:1+2+3+...+n=n(n+1):2

2(200x201:2)=2x40200:2=2x20100=40200

3+6+9+.........+600=
3(1+2+3+......+200)=
3(200x201:2)=3x20100=60300