High School

Here is a formula to convert degrees Celsius [tex]\(\left({ }^{\circ} C \right)\)[/tex] to degrees Fahrenheit:

[tex]\[ F = 1.8C + 32 \][/tex]

Where [tex]\( F \)[/tex] is the number of degrees Fahrenheit, and [tex]\( C \)[/tex] is the number of degrees Celsius.

1. If the temperature in degrees Celsius is [tex]\(-5\)[/tex], what is the temperature in degrees Fahrenheit?

2. Which temperature is the same in degrees Celsius as it is in degrees Fahrenheit?

Answer :

We start with the conversion formula from Celsius to Fahrenheit:
[tex]$$
F = 1.8C + 32.
$$[/tex]

1. To find the Fahrenheit temperature when the Celsius temperature is [tex]$-5^\circ C$[/tex], substitute [tex]$C = -5$[/tex] into the formula:
[tex]$$
F = 1.8(-5) + 32.
$$[/tex]
First, multiply:
[tex]$$
1.8 \times (-5) = -9.
$$[/tex]
Then add 32:
[tex]$$
F = -9 + 32 = 23.
$$[/tex]
So, the temperature in Fahrenheit is [tex]$23^\circ F$[/tex].

2. Next, to find the temperature at which the numerical value in Celsius equals the numerical value in Fahrenheit, set [tex]$C = F$[/tex]. Replace [tex]$F$[/tex] in the conversion formula by [tex]$C$[/tex]:
[tex]$$
C = 1.8C + 32.
$$[/tex]
Subtract [tex]$1.8C$[/tex] from both sides to isolate the term containing [tex]$C$[/tex]:
[tex]$$
C - 1.8C = 32.
$$[/tex]
Combine like terms:
[tex]$$
-0.8C = 32.
$$[/tex]
Divide both sides by [tex]$-0.8$[/tex] to solve for [tex]$C$[/tex]:
[tex]$$
C = \frac{32}{-0.8} = -40.
$$[/tex]
Therefore, the temperature that is the same in both Celsius and Fahrenheit is [tex]$-40^\circ$[/tex].

In summary:
- Converting [tex]$-5^\circ C$[/tex] gives [tex]$23^\circ F$[/tex].
- The temperature that is the same in both units is [tex]$-40^\circ$[/tex].