Question

The formula C = 5 (F − 32) can be used to convert Fahrenheit temperatures F to 9 Celsius temperatures C. For what Fahrenheit temperatures is the Celsius temperature lower than 45 degrees C?

Answer 1

The given formula C=5(F-32) should properly read C=(5/9)(F-32), or
9C=5(F-32).
Using the corrected formula, F=(9C/5)+32, so for C<45,
F<(9*45/5)+32=113 degrees
Incidentally, these are the temperatures that yeast can survive. Above 45 degrees C, they might die of heat!