Binomial Expansion

One of the terms in the binomial expansion of $2 + bx)^5$ , where $b\,$ is a constant, is $720x^2$ .

a.

Find the possible values of $b$ .

[3]

b.

Hence find the term independent of $x\,$ in the expansion of

\left( \frac{1}{4} + \frac{1}{x^5} \right) (2 + bx)^5

[3]

One of the terms in the binomial expansion of $2 + bx)^5$ , where $b\,$ is a constant, is $720x^2$ .

a.

Find the possible values of $b$ .

[3]

b.

Hence find the term independent of $x\,$ in the expansion of

\left( \frac{1}{4} + \frac{1}{x^5} \right) (2 + bx)^5

[3]

Binomial Expansion Questions