Which form of the quadratic equation is this??

Need help ASAP plzz

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 domain of the following relation: r: {(3, 5), (8, 6), (2, 1), (8, 6)} is (1 point) no domain exists {1, 5, 6} {3, 8, 2, 8} {2, 3, 8}

Abari owns 100 shares of stock a and 45 shares of stock b. for the past month, his stocks have been fluctuating inversely. stock a decreased by m cents per share and stock b increased by n cents per share. which equation can be used to find the total change in value of jabari's shares per month?