What is the area of this parallelogram

Complete the equation of the live through (-1,6) (7,-2)

Find the center of the circle that can be circumscribed about efg with e(4,4) f(4,2) g(8,2)

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?