# How do you solve this?

## The temperature is 4∘ Celsius. Find the temperature in Fahrenheit. $C = \frac{5}{9} \left(F - 32\right)$

Dec 20, 2016

If $C = 4$, $F = 39.2$.

#### Explanation:

You have an equation that takes in $F$ values and spits out $C$ values.

You want an equation that takes in $C$ values and spits out $F$ values.

Start with $C = \frac{5}{9} \left(F - 32\right)$.

Multiply both sides by $\frac{9}{5}$ to get $\frac{9}{5} C = F - 32$.

Add $32$ to both sides to get $\frac{9}{5} C + 32 = F$.

So $F = \frac{9}{5} C + 32$.

So if $C = 4$, $F = \frac{9}{5} \left(4\right) + 32 = 39.2$.