Final answer:
When the temperature drops 4°F from an initial temperature of -3°F, the resultant temperature is -7°F.
Step-by-step explanation:
If the temperature is -3°F at 10:00 pm and the temperature falls 4°F overnight, the resultant temperature can be calculated by subtracting 4°F from -3°F. To do this mathematically, you would express the temperature drop as -4°F since it is a decrease, and then add this value to the initial temperature:
-3°F + (-4°F) = -7°F
The resultant temperature would therefore be -7°F.