Find the Derivative of the Function $k ( x ) = \frac { 6 x ^ { 12 } - 9 x ^ { 16 } } { x ^ { 6 } }$

Essay

Find the derivative of the function.
​ $k ( x ) = \frac { 6 x ^ { 12 } - 9 x ^ { 16 } } { x ^ { 6 } }$