x+2x+3x+...+2011x=2011x2016

Răspuns :

X+2x+3x+...+2011x=2011x2016
x(1+2+3+.....+2011)=2011x2016
x(2011x2012:2)=2011x2016
x=2011x2016:2011x1006
x=2016:1006