At 9:00 pm the outside temperature was 20 celcius, by midnight the temperature had dropped x degrees.
Which of the following represents the midnight temperature?
20 + x
20-x
20
20x
20-x, because it DROPPED x degrees.
To find the midnight temperature, we need to use the information given.
At 9:00 pm, the outside temperature was 20 degrees Celsius. From 9:00 pm to midnight, the temperature dropped x degrees.
Since the temperature dropped, we need to subtract x from the initial temperature of 20 degrees Celsius.
Therefore, the correct representation for the midnight temperature is 20 - x.