A scientist measured the temperature at sunrise and found that it was 9°C. She continued measuring each hour and saw that it rose 1°C each time.

Question

Write an equation that shows the relationship between the number of hours, x, and the temperature in °C, y.

Answer 1

To describe the relationship between the number of hours \( x \) and the temperature in °C \( y \), we can use the following linear equation:

\[ y = 9 + x \]

In this equation:

• \( y \) represents the temperature in °C,
• \( x \) represents the number of hours since sunrise,
• The starting temperature at sunrise is 9°C, and the temperature increases by 1°C for each hour (\( x \)).

So, when \( x = 0 \) (at sunrise), \( y = 9 + 0 = 9 \). For each subsequent hour, \( y \) increases by 1°C.