Here's the formula you need.
It converts any Fahrenheit temperature into the corresponding
Celsius number. Just write the Fahrenheit number in place of 'F',
and then figure out what 'C' is.
C = 0.55 (F - 32) .
So, for the problem in the picture, write
C = 0.55 (320 - 32)
and then just simplify it down and find 'C'.
