Can someone help me with this problem?

Question

𝐶=5/9(𝐹−32)

At the top of Mount Everest, your American climbing friend can announce that his smartwatch shows that the temperature is - 31 degrees Fahrenheit. What is the temperature in degrees Celsius?

Answer 1

C=(5/9)(F-32)

C=(5/9)(-31-32) = (5/9)(-63) = (5)(-7) = -35

C= -35 degrees Celsius when F=-31

F-32 = 9C/5

F= 9C/5 + 32

F= 9(-35)/5 +32 = 9(-7)+32 = -63+32 = -31 when C=-35