Question

(2+4+6+8+...+200)-(1+3+5+7+...+199) AJUTOR DAU COROANA

Answer 1

(2+4+6+8+......+200)-(1+3+5+7+.....+199)=

2-1+4-3+6-5+8-7+.....+200-199=

1+1+1+1+.....+1=

100nr pare,si 100 nr impare  100 perechi care dau rezultatul 1

100*1=100

Answer 2

2(1+2+...100)-((2*0+1)+(2*1+1)+(2*2+1)+...+(2*99+1))=

2*100*101/2-(2(1+2+..+99)+100)=

10100-2*99*100/2+100=

10100-9900-100=

100