At what temperature are the celsius and fahrenheit scale reading equal
Answers
The formulas for converting between degree Celsius and degree Fahrenheit are:
°F = (°C * 9/5) + 32
°C = (°F - 32) * 5/9
To find the temperature when both are equal, we use an old algebra trick and just set ºF = ºC and solve one of the equations.
°C = (°C * 9/5) + 32
°C - (°C * 9/5) = 32
-4/5 * °C = 32
°C = -32 * 5/4
°C = -40
°F = (°F * 9/5) + 32
°F - (°F * 9/5) = 32
-4/5 * °F = 32
°F = -32 * 5/4
°F = -40
So the temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Let x be the common reading.
Then, C = F = x
Using the formula, C=5/9 (F-32),and substituting x for C and F, we get
x =5/9 (x-32)
x =5/9x - 5/9×32
x - 5/9x = 5×32/9
4/9x = - 5×32/9
x = - 5×32/4 = -40
So, -40C = -40F
Hence, at -40 degrees , the readings on the Celsius scale and the Fahrenheit scales are rhe same.