ºF = Fahrenheit
  ºC = Celsius
  K = Kelvin 
ºF - 32 = 9/5 ºC  | 
  ||
solved for ºF...  | 
    solved for ºC...  | 
  |
ºF = 9/5 ºC + 32  | 
    ºC =  (ºF - 32) 5/9  | 
  |
5 (ºF) - 9 (ºC) = 160
|  
      
       Add 40, 
     | 
     
       multiply ºF by 5/9 
     | 
    
      
       , subtract 40 
     | 
  
|  
       multiply ºC by 9/5 
     | 
  
K = ºC + 273.15
  ºC = K - 273.15