Suppose $f(x) = \left(5-6x\right)\!\left(2x-4\right)^{2}$.

(a) The roots of $f(x)$ are $x =$ help (numbers) (If a root is repeated, enter it only once.)

(b) As $x \to \infty$, $f(x) \to$ help (numbers)

(b) As $x \to -\infty$, $f(x) \to$ help (numbers)