\[(m - 2)(m - 1) - (m + 3)(m - 5);\]
\[m = 3:\]
\[(3 - 2)(3 - 1) - (3 + 3)(3 - 5) =\]
\[= 1 \cdot 2 - 6 \cdot ( - 2) = 2 + 12 = 14.\]