A complex number can be defined as $ j = \sqrt(-1) $
$ j^1 = j $
$ j^2 = -1 $
$ j^3 = -j $
$ j^4 = 1 $
$ (a+bj)+(c+dj) = (a + c) + (c + d)j $
$ (a+bj)/(c+dj) = $
