3.76: Binomial expansions and a term independent of xx

0606/21/M/J/22 — Question 5 · 7 marks · Binomial

(a)(i)
Write down, in ascending powers of xx, the first three terms in the expansion of (1+4x)n(1 + 4x)^{n}. Simplify each term.
[2]
(a)(ii)
In the expansion of (1+4x)n(14x)(1 + 4x)^{n}(1 - 4x), the coefficient of x2x^{2} is 6032. Given that n>0n > 0, find the value of nn.
[3]
(b)
Find the term independent of xx in the expansion of (x28x4)10\left(\dfrac{x}{2} - \dfrac{8}{x^{4}}\right)^{10}.
[2]