Your On-Line Bookstore Is in Direct Competition with Amazon $R ( x , y , z ) = 15,000 - 0.02 x - 0.01 y - 0.02 z + 0.0001 y z$

Essay

Your on-line bookstore is in direct competition with Amazon.com, BN.com, and Borders.com. Your company's daily revenue in dollars is given by
​ $R ( x , y , z ) = 15,000 - 0.02 x - 0.01 y - 0.02 z + 0.0001 y z$ ​
where x, y, and z are the online daily revenues of Amazon.com, BN.com, and Borders.com, respectively. If Amazon.com and BN.com each show a daily revenue of $5,000, give an equation showing how your daily revenue depends on that of Borders.com.