Question

X+(x+2)+(x+4)+....+(x+2000)=1001.1002

Answer 1

x+(x+2)+(x+4)+....+(x+2000)=1001*1002
x+(x+x+...de 1000 de ori...+x)+(2+4+...+2000)=1001*1002
1001x +2(1+2+...+1000)=1001*1002
1001x +2(1000*1001)/2=1001*1002
Am aplicat formula lui Gauss: 1+2+...+n=n(n+1)/2
1001x +1000*1001=1001*1002
Impartim prin 1001:
x+1000=1002
x=2