Help me plss, i will give brainliest

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

Need solving this second acceleration problem.

240 seventh graders and two-thirds of the students participate in after-school activities how many students participate in after-school activities