Veronica earned $150 at work this past week in her paycheck. She wants to buy some necklaces which costs $6 each. She writes a function to model the amount of money she will have left from her paycheck after purchasing a certain number of necklaces. She writes the function, f(x)= 15 - 6x. Determine what x and f(x) stand for in the function.

(1) x=weeks; f(x)= dollars left 

(2) x=dollars left; f(x)= weeks

(3) x=necklaces; f(x)= dollars left

(4) x=dollars left; f(x)= necklaces