Juan is a software salesman. Let&nbspy&nbsprepresent his total pay

Juan is a software salesman. Let y represent his total pay (in dollars). Let x represent the number of copies of History is Fun he sells. Suppose that x and y are related by the equation =+2100+70xy .Answer the questions below.Note that a change can be an increase or a decrease.For an increase, use a positive number. For a decrease, use a negative number.