Ryan is a software salesman. Let represent his total pay (in dollars). Let represent the number of copies of Math is Fun he sells. Suppose that x and y are related by the equation y=2400+70x. 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.
What is Ryan's total pay if he doesn't sell any copies of Math is Fun?

What is the change in Ryan's total pay for each copy of Math is Fun he sells?