Temperatures measured in degrees Fahrenheit (F) are related to

Temperatures measured in degrees Fahrenheit (F) are related to temperatures measured in degrees Celsius (C) by the formula F = 9C/5 + 32. There is 1 value of x for which x degrees Fahrenheit equals x degrees Celsius. What is that value?

  1. -72
  2. -40
  3. -32
  4. 0
  5. 32

Answer

The correct answer is B.

For the temperature we are looking for, F = C = x.

Substituting x for both C and F into the given formula, we get

x = 9x/5 + 32

Multiplying both sides of this equation by 5, combining like terms, and solving for x, we get

5x = 9x + 160

4x = -160

x = -40