Question 17312
Notice first that 256 is a perfect square, since {{{16^2 = 256}}}.  
Second, remember from complex numbers that {{{i^2 = -1}}}.  Using this you can write:
{{{x^2+ 256= s^2 - 256i^2}}}, which is a difference of squares that factors.  
(s-16i)(s+16i)


R^2 at SCC