Question

What is the coefficient of `x^2` in the expansion of `(x+2)^3`?

Answer 1

The coefficient of `x^2` in the expansion of `(x+2)^3` is `6`

Explanation:

Binomial expansion of `(x+a)^3` is

`x^3+^3C_1x^2a+^3C_2xa^2+^3C_3a^3`

Hence coefficient of `x^2` in `(x+2)^3` is

`color(white)+^3C_1xx2`

= `3xx2=6`