Fill in the blanks with integers to get an identity.
(n - k + 2)^2 = __ n^2 + ___ k^2 + ___ n + ___k + ___ nk + ___
Use the identity \((a + b + c)^2 = a^2 + b^2 +c^2 +2ab+2bc+2ca\).
\((n -k + 2)^2 = \textcolor{red}{1}n^2 + \textcolor{red}{1}k^2 + \textcolor{red}{4}n + \textcolor{red}{(-4)}k + \textcolor{red}{(-2)}nk + \textcolor{red}{4}\).