(2x + 1) + (2x + 2) + ... + (2x + 2015) = 0
=> 2x + 2x + ... + 2x + (2015 + 1).2015 : 2 = 0
=> 2015.2x + 2031120 = 0
=> 4030x = -2031120
=> x = -504
(2x + 1) + (2x + 2) + ... + (2x + 2015) = 0
=> 2x + 2x + ... + 2x + (2015 + 1).2015 : 2 = 0
=> 2015.2x + 2031120 = 0
=> 4030x = -2031120