Absurdly Complicated (to me) Factoring Problem

I was given a review handout for a Calc. + Anal. Geom. (lol!) and I ran into an inconspicuously confusing factoring problem:

54ał - 16bł

I factored it to 2(27ał - 8bł), but he got to

2(3a - 2b)(9a˛ + 6ab + 4b˛)…

May someone please explain to me how solving this this was expected to be innate algebraic practicality?

…or please explain how he might have gotten to his solution. From there, I hope I'd be able to tackle almost any similarly ridonque. factoring problem…