\[\frac{q^{2} - 4q - 5}{3}\]
\[при\ \ q = 1,2:\]
\[\frac{1,44 - 4,8 - 5}{3} = \frac{- 8,36}{3} =\]
\[= \frac{- 836}{300} = - 2\ \frac{236}{300} = - 2\ \frac{118}{150} =\]
\[= - 2\frac{59}{75}.\]