As it turns to night it says the temperature decreases by 12.1 and during the day the temperature is doubled. We are given the night temp so we need to work backwards. Start with the given temp of -6.5 and then add the 12.1 because we are now trying to go from night to before the sun went down. And if when the sun goes down it takes 12.1 away if we want the sun to go back up we have to add it cause its the opposite. Then it says in the day the temp is doubled so then we are going to double our number we just got by multiplying it by 2.
