In Equation -2 (or Equation -1), set C = F:

**∴F = (5/9)(F – 32) ⇒ 9F = 5F – 160 ⇒ 4F = -160 ⇒ F = -40 °F**

Check Equation 1 & 2 in below link -

In Equation -2 (or Equation -1), set C = F:

**∴F = (5/9)(F – 32) ⇒ 9F = 5F – 160 ⇒ 4F = -160 ⇒ F = -40 °F**

Check Equation 1 & 2 in below link -