Question 1093588:  The relationship between Fahrenheit temperature, F, and Celsius temperature, C, is shown by the formula F = C + 32. At what temperature will a Fahrenheit thermometer read the same as a Celsius thermometer? 
 Found 3 solutions by  Alan3354, ikleyn, Boreal: Answer by Alan3354(69443)      (Show Source): 
You can  put this solution on YOUR website! formula F = C + 32 
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Using that, never. 
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F = (9/5)C + 32 
F = 1.8C + 32 
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C = 1.8C + 32 
-0.8C = 32 
C = -40 
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-40C = -40F 
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That's close to the freezing point of Hg, -39.6. 
I forget if that's C or F, but I doesn't matter here. 
 
 Answer by ikleyn(52903)      (Show Source):  Answer by Boreal(15235)      (Show Source): 
You can  put this solution on YOUR website! The answer is -40, and here is how you get there.
 
C=(5/9)(F-32) 
but C=F 
therefore, F=(5/9)(F-32)=(5/9)F-160/9 
(4/9)F=-160/9 
denominators cancel 
4F=-160 
F=-40=C
 
 
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