Question

How do you multiply `(sqrt6 +6c)(sqrt6 -6c)`?

Answer 1

You can recognise this as being of the form `(a+b)(a-b) = a^2-b^2`

So:

`(sqrt(6)+6c)(sqrt(6)-6c) = (sqrt(6))^2-(6c)^2=6-36c^2`