Question

Find the cube of: `3"a" + (1)/(3"a")`

Answer 1

`(3"a" + 1/(3"a"))^3`

= `(3"a")^3 + (1/(3"a"))^3 + 3 (3"a") (1/(3"a")) (3"a" + 1/(3"a"))`

= `27"a"^3 + (1)/(27"a"^3) + 9"a" + (1)/"a"`.