\[ \left( \begin{array}{cccc}
a & b & c & d \\
e & f & g & h \\
i & j & k & l \\
m & n & o & p \end{array} \right)\] = a\[ \left( \begin{array}{ccc}
f & g & h \\
j & k & l \\
n & o & p \end{array} \right)\] - e\[ \left( \begin{array}{ccc}
b & c & d \\
j & k & l \\
n & o & p \end{array} \right)\] + i\[ \left( \begin{array}{ccc}
b & c & d \\
f & g & h \\
n & o & p \end{array} \right)\] - m\[ \left( \begin{array}{ccc}
b & c & d \\
f & g & h \\
j & k & l \end{array} \right)\]