\[\boxed{\mathbf{929\ (929).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ 2a - 6 = 2 \cdot (a - 3) > 0\]
\[2)\ 15 - 5a = 5 \cdot (3 - a) < 0\]
\[3)\ 2a - 4 = 2 \cdot (a - 2) > 0\]
\[4)\ (a - 3)(2 - a) < 0\]
\[5)\ \frac{a - 2}{a - 1} > 0\]
\[6)\ \frac{- 4}{3 - a} > 0\]