\[2pq - 2p - p + 2q =\]
\[= 2pq - 3p + 2q;\]
\[p = - 3;\ q = - 7:\]
\[2 \cdot ( - 3) \cdot ( - 7) - 3 \cdot ( - 3) + 2 \cdot ( - 7) =\]
\[= 42 + 9 - 14 = 37.\]