B3. Temperature measurement in degrees Celsius ( $\left.^{\circ} \mathrm{C}\right)$, and in some places, degrees Fahrenheit ( ${ }^{\circ} \mathrm{F}$ ) are used. Both methods are connected by the equation $T_{F}=\frac{9}{5} T_{C}+32$, where $T_{F}$ represents the temperature in degrees Fahrenheit, and $T_{C}$ represents the temperature in degrees Celsius.

A How many ${ }^{\circ} \mathrm{F}$ is $10^{\circ} \mathrm{C}$ ?

B How many ${ }^{\circ} \mathrm{C}$ is $14^{\circ} \mathrm{F}$ ?

C Draw a graph of temperature in Fahrenheit as a function of temperature in Celsius.
B3. A $10^{\circ} \mathrm{C}$ is $\frac{9}{5} \cdot 10+32=50^{\circ} \mathrm{F}$.

B The sought temperature $T_{C}$ is the solution to the equation $14=\frac{9}{5} \cdot T_{C}+32$. The temperature $T_{C}=-10^{\circ} \mathrm{C}$.

C The dependence of Fahrenheit temperature on Celsius temperature is shown in the graph:

![](https://cdn.mathpix.com/cropped/2024_06_07_dba92f8afafce9b63777g-7.jpg?height=1051&width=785&top_left_y=200&top_left_x=721)

Scoring: Total: 7 points
A Writing the equation: $T_{F}=\frac{9}{5} \cdot 10+32$ ..... 1 pt
Calculated temperature in Fahrenheit: $T_{F}=50^{\circ} \mathrm{F}$ ..... 1 pt
B Writing the equation: $14=\frac{9}{5} \cdot T_{C}+32$ ..... 1 pt
Calculated temperature in $^{\circ} \mathrm{C}: T_{C}=-10^{\circ} \mathrm{C} \ldots$ ..... 1 pt
C Correctly labeled axes ..... 1 pt
Correctly drawn line ..... 1 pt
Accuracy, e.g., the y-axis intersects at 32 and passes through the point $(10,50)$ or well-marked appropriate points through which the line passes. ..... 1 pt