Which of the following sets is closed under division?

The graph of f(x)=|x| is reflected over the y-axis and horizontally compressed by a factor of 1/9. write a formula for function g(x)

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.