2 less than six times a number

6n-2

Why?

Let n represent the number.

It says "six times" the number, so we need to put in 6n.

It says "2 less" than 6n, which means we need a - 2. This number goes after 6n, since it says "than." Had it go in front, it would've been written as such: 2 decreased by 6 times a number (or something similar to that).