At what temperature will fahrenheit and celsius readings be the same numerically but opposite in sign?

Question

At what temperature will fahrenheit and celsius readings be the same numerically but opposite in sign?

Answer 1

-40 degrees.....

Answer 2

x = (-x-32)*5/9

9x = (-x-32)5

9x = -5x -160

14x = -160

x = -11.43

-11.43°C = +11.43°F

Answer 3

Oh, surely you can figure this out for yourself, knowing that the freezing point of water measured in degrees Celsius is zero and measured in degrees Fahrernheit is 32 degrees,