1.10: Binomial expansion and term independent of $x$

Find the first 3 terms in the expansion of $\left(4 - \tfrac{x}{16}\right)^{6}$ in ascending powers of $x$. Give each term in its simplest form.

Hence find the term independent of $x$ in the expansion of $\left(4 - \tfrac{x}{16}\right)^{6}\left(x - \tfrac{1}{x}\right)^{2}$.