Answer:
a drop of 5 degree F, or -5 °F
Explanation:
You want to know the total change in temperature after a drop of 2 degree F and a second temperature drop of 3 degree F.
Change
The total change will be the sum of changes.
We can figure the total drop in temperature as the sum of drops:
2 °F +3 °F = 5 °F . . . . the total drop in temperature
If we use negative values to represent temperature drops, then the total change can be written as ...
(-2 °F) +(-3 °F) = -5 °F . . . . . the total change in temperature
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Additional comment
We often find it convenient to use negative numbers to represent decreases, drops, amounts below some reference level, and so on. Positive numbers can be used for the same purpose if we define the meaning of a positive number in the context.
Here, we can identify a temperature drop by saying it is a drop of 5 degrees, where a positive temperature drop means a change to a lower value. Or, we can say it is a change of -5 degrees, where a positive change is defined as a change to a higher value.
Defining the meaning of positive and negative numbers is especially important when an "improvement" is a reduction in some value (cost, for example). A positive improvement may mean a negative change, and vice versa.