Answer:
-172.6 °C
Step-by-step explanation:
You want to know the Celsius equivalent of the temperature 100.6 K.
Conversion
The relation is ...
C = K - 273.15
C = 100.6 -273.15 = -172.55
The temperature is -172.55 °C, about -172.6 °C.
__
Additional comment
We have rounded to tenths, because that is precision of the temperature given. If you use 273 as the conversion constant, you will get -172.4.