Last year's linear equation

$\displaystyle \frac {x + 2016}{2017} = \frac {x + 2017}{2016}$

$\displaystyle 2016x + 2016^2 = 2017x + 2017^2$

$\displaystyle x + 2017^2 - 2016^2 = 0$

$\displaystyle x + (2017 - 2016)(2017 + 2016) = 0$

$\displaystyle x + 4033 = 0$

$\displaystyle |x| = 4033$