Nilai x yang memenuhi adalah....

x = 1/2013 - 2/2013 + 3/2013 + 4/2013 + ... + 2011/2013 - 2012/2013
= (1 - 2 + 3 - 4 + ... + 2011 - 2012) / 2013
= ((1 - 2) + (3 - 4) + ... + (2011 - 2012)) / 2013
= ((-1) + (-1) + .... + (-1)) / 2013 =======> (-1) nya sebanyak 2012 : 2 = 1006
= (-1) (1006) / 2013
= -1006 / 2013