Answer:
The temperature in 5 hours will be -25°C.
The temperature 8 hours ago was 14°C.
Explanation:
To find the temperature, y, in degrees Celsius at any given number of hours, x, from the current time, we can create a linear equation in the form y = mx + b, where m is the rate of change and b is the current temperature.
Given the current temperature is -10°C, then b = -10.
Given the temperature falls at a constant rate of 3°C per hour, then m = -3.
Substitute the values of m and b into the formula:

where:
- y is the temperature in °C.
- x is the number of hours.
To calculate the temperature in 5 hours time, substitute x = 5 into the equation:

Therefore, the temperature in 5 hours will be -25°C.
To calculate the temperature 8 hours ago, substitute x = -8 into the equation. The value of x is negative since we want to find the temperature 8 hours before the current time.

Therefore, the temperature 8 hours ago was 14°C.