Macy has a 20 year adjustable rate mortgage with a fixed rate for the first 7 years. in the 8th year, the interest rate rises to 6.2%. the remaining balance at the end of the 7th years is $398,381.20. what is the monthly payment in the 8th year?

The john deere company has found that revenue, in dollars, from sales of heavy-duty tractors is a function of the unit price p, in dollars, that it charges. if therevenue r is r(p)= -1/2p^2 +1900pa)how much revenue will the company generate if they sell 700 tractors? b) how many tractors does the company want to sell to maximize the revenue?