There are 1 private rooms in a large hotel in Kaili. During the business hours of dinner every day, when each private room charges 1 yuan, all the private rooms can be rented out. If every room

(2), that is, y, because before the price increase, the total income of room fees was 1×1=1. When x=5, the maximum private room income can be 1125 yuan, and 1125 >: 1。 And because every time the price is raised to 2 yuan, the dinner in each private room should be raised to 4 yuan or 6 yuan.