Help pls

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

8. kelly wants to buy a magazine that is $25. later the magazine was marked up an additional 20%. what is the new price?