Question

In countries like USA and Canada, the temperature is measured in Fahrenheit, whereas in countries like India, it is measured in Celsius. Here is a linear equation that converts Fahrenheit to Celsius:
$F=\frac{9}{5}C+32$
(i) Draw the graph of the linear equation above using Celsius for x-axis and Fahrenheit for the y-axis.
(ii) If the temperature is ${30}^{\circ }C$, what is the temperature in Fahrenheit?
(iii) If the temperature is ${95}^{\circ }F$, what is the temperature in Celsius?

Answer 1

$\left(i\right)F=\frac{9}{5}C+32$
When $C=0$ then $F=32$
also, when $C=5$ then $F=41$

$\begin{array}{ccc}C& 0& 5\\ F& 32& 41\end{array}$


(ii) Putting the value of $C=30$ in $F=\frac{9}{5}C+32$, we get
$F=\frac{9}{5}\times 30+32$
$\Rightarrow F=54+32$
$\Rightarrow F=86$
(iii) Putting the value of $F=95$ in $F=\frac{9}{5}C+32$, we get
$95=\frac{9}{5}C+32$
$\Rightarrow \frac{9}{5}C=95-32$
$\Rightarrow C=63\times \frac{5}{9}$
$\Rightarrow C=35$