Thanks coolul007, haven't really been shown the Distributive way of working with squares like that, has helped shed some light on another tricky simplication.
Hoping someone can push me in the right direction with this one. Plume snookered.
It's to simplify:
2√3(3+√3)
Guessing first calculate (a^2 - b^2*c) in the square, though the 2 is throwing this an I'm not sure how the answer is 6√3 + 6, an not 18√3 ?