6. (a) Find, in ascending powers of \(x\), up to and including the term in \(x ^ { 3 }\), the binomial expansion of
$$\left( 1 + \frac { 1 } { 4 } x \right) ^ { 12 }$$
giving each term in its simplest form.
(b) Hence find the coefficient of \(x\) in the expansion of
$$\left( 3 + \frac { 2 } { x } \right) ^ { 2 } \left( 1 + \frac { 1 } { 4 } x \right) ^ { 12 }$$