Question

Factorise.

`a^3 + 8/a^3`

Answer 1

It is known that,

a³ + b³ = (a + b)(a² − ab + b²)

`a^3 + 8/a^3`

= `(a^3) + (2/a)^3`

= `(a + 2/a) {(a)^2 + (2/a)^2 - (a) xx (2/a)}`

= `(a + 2/a)(a^2 + 4/a^2 - 2)`