Lou says "even if you tripled you age", which means that if Audrey's age is represented by the variable x, then we would multiply it by 3 to get 3x. the next part says "and add 9". We already have the 3x, so we would just tack on a +9 to get 3x + 9. The last part says "you still wouldn't be as old as me." Given that 3x+9 represents Audrey's age, this equation would have to be less than Lou's age, which in this case is 60.