A company that manufactures cell phones has done research to determine how the pricing of thier phones affects how many they sel
l and how much money they make. They have determined that if p is the price of a phone in dollars, the following equations model thier cost, C, and revenue, R. C=500+200p and R= -p^2+800. What range can they price the cell phones so there will be a profit A. Less than $130 or more than $770
