Question

How much is 70 degrees Fahrenheit in Celsius?

Answer 1

`70^@F = 21.bar(1)^@C`

Explanation:

To convert Fahrenheit to Celsius, the normal method is to subtract `32` then divide by `1.8` (i.e. `9/5`).

So in our example:

`5/9(70-32) = 5/9(38) = 190/9 = 21.bar(1)`

Alternatively, since `-40^@F = -40^@C`, we can convert by adding `40`, multiplying by `5/9`, then subtracting `40`:

`5/9(70+40)-40 = 5/9(110)-40 = 550/9 - 40 = 61.bar(1)-40 = 21.bar(1)`

The reverse conversion from Celsius to Fahrenheit can be done by either of the following:

• Multiply by `9/5` then add `32`.

• Add `40`, multiply by `9/5`, then subtract `40`.