Show that the temperature -40° is unique in that it has the same numerical value on the Celsius and

Fahrenheit scales.

F = 1.8*C + 32

Let C = -40

F = 1.8*(-40) + 32
F = -72 + 30
F = -40

It is unique because the relationship is linear in one variable. There can be, at most, one solution

Let the temperature which is same in both scales is x°

from the relation

F-32/180=C/100

putting F=C =x

x-32/180=x/100
=>10x-320=18x
=>8x=-320
=>x=-40°

hence -40° is unique in that it has the same numerical value on the Celsius and?
Fahrenheit scales.

http://www.google.com/search?q=-40+C+to+…
http://www.google.com/search?q=-40+F+to+…