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