Answer:
-4°C
Key:
( | | ) = these in between numbers is the absolute value. EXAMPLE: |-8| = 8
Explanation:
If it was -9°C and it INCREASED by 5°C, you need to ADD.
-9°C + 5°C
*Because -9°C is a NEGATIVE NUMBER and is on the LEFT side of the number line, unlike 5°C, you need to count 5 units to the RIGHT of -9°C (Basically subtract the absolute values of each number (-9 = |9|) (5 = |5|) and make it either positive or negative, depending on which absolute value is the greatest (|9|).*
-9°C + 5°C OR |9| - |5|
|9°C| - |5°C| = |4°C| = -4°C
(because the greatest absolute value, |9|, is negative, the answer is too.)
HOPE THIS HELPS :D