A farmer here's a weather report saying that temperatures will be decreasing approximately 6∘ 6∘ every hour for the next 5 hours. what signed number represents the total change in temperature expected over the next 5 hours

Because temperature is decreasing we can say that after one hour new temperature is - 6° from starting temperature.

After 5 hours temperature will drop:

5 * (-6) = - 30 because temperature decrease is constant on each hour.

The answer is - 30°