Answer:
The answer is 110 degrees C.
Step-by-step explanation:
The melting point of substance X is -20 degrees Celsius and the boiling point is 90 degrees Celsius.
To find the difference between the degrees, we will subtract the values.
So, the difference between these points will be =
[tex]90-(-20)[/tex]
= [tex]90+20=110[/tex]
The answer is 110 degrees C