Positive and Negative Quantities 2

At 8:00 a.m., the thermometer reads −1°. From 8:00 a.m. to 11:00 a.m., the temperature drops at a rate of 2° per hour, and from 11:00 a.m. to 2:00 p.m., it rises at a rate of 3° per hour. Express the temperature at 10:00 a.m., 11:00 a.m., 12:00 p.m., and 2:00 p.m.