Question

4. The relationship between temperature expressed in degrees Fahrenheit(F) and degrees Celsius (C) is given by the formula F= (9/5)C + 32. If the temperature is 5 degrees Fahrenheit, what is it in degrees Celsius ?

Answer 1

To calculate which value in Celsius the temperature of 5 Fº equates to, we first need to rewrite the expression isolating the "C" variable on the left side.

`\begin{gathered} F=(9)/(5)\cdot C+32 \\ (9)/(5)\cdot C=F-32 \\ 9\cdot C=5\cdot F-160 \\ C=(5)/(9)\cdot F-(160)/(9) \\ \end{gathered}`

We now need to replace F by 5.

`\begin{gathered} C=(5)/(9)\cdot5-(160)/(9) \\ C=(25)/(9)-(160)/(9) \\ C=(-135)/(9) \\ C=-15 \end{gathered}`

The temperature is -15 degrees in Celsius.