Question 12 Marks
The linear equation that converts Fahrenheit $(F)$ to Celsius $(C)$ is given by the relation, $\text{C}=\frac{5\text{F}-160}{9}$ What is the numerical value of the temperature which is same in both the scales?
Answer
View full question & answer→$\text{C}=\frac{5\text{F}-160}{9}$ putting $C = F,$ in the given relation,
we get $\text{F}=\frac{5\text{F}-160}{9}$
$\Rightarrow9\text{F}=5\text{F}-160$
$\Rightarrow4\text{F}=160$
$\therefore\text{F}=\frac{-160}{4}=-40^\circ$
Hence, the numarical value of the temperature which is same in both the scales is $-40.$
we get $\text{F}=\frac{5\text{F}-160}{9}$
$\Rightarrow9\text{F}=5\text{F}-160$
$\Rightarrow4\text{F}=160$
$\therefore\text{F}=\frac{-160}{4}=-40^\circ$
Hence, the numarical value of the temperature which is same in both the scales is $-40.$
You can see that the graph (line $AB$) cuts the $X-$axis at the point $(2, 0)$ and the $Y-$axis at the point $\Big(0,\frac{3}{2}\Big).$