\[48 = 11 - (9a + 2)\]
\[48 = 11 - 9a - 2\]
\[9a = - 48 + 9\]
\[9a = - 39\]
\[a = - \frac{39}{9} = - 4\frac{3}{9}\]
\[a = - 4\frac{1}{3}.\]