Let d {\displaystyle {}d} be a fixed positive natural number. Show that, for every integer number n {\displaystyle {}n} , there exists a uniquely determined integer number q {\displaystyle {}q} and a uniquely determined natural number r {\displaystyle {}r} , 0 ≤ r ≤ d − 1 {\displaystyle {}0\leq r\leq d-1} , such that
holds.