what is the linear equation relating celsius and fahrenheit if 0 celsius corresponds to 40 celsius corresponds to 104 fahrenheit

Question

what is the linear equation relating Celsius and Fahrenheit degrees if 0 Celsius corresponds to 32fahrenheit and 40 Celsius corresponds to 104fahrenheit  if the Celsius  measure is 64fahrenheit?

Answer 1

 Water freezing point is set in Celsius to 0, and boiling water at 100.

 Water freezing point is set in Fahrenheit 32, and boiling water at 212

 

    Then if we let  each 1/100 point of Celsius equal to ( F -32) / 180,

 

     C   = F - 32 

     100    180

        C  = F - 32

        5        9

       then     9C = 5F - 160

 

            5F = 9C - 160

        F    =  9/5  C + 32

               

Answer 2

Tf =  9/5Tc + 32