\[3a + 5 - (2a + 6) + 4a =\]
\[= 3a + 5 - 2a - 6 + 4a = 5a - 1\]
\[a = - 10:\]
\[5 \cdot ( - 10) - 1 = - 50 - 1 = - 51.\]
\[Ответ:\ - 51.\]