Answer:
The temperature in degrees after 9 hours is -1.25 degrees Fahrenheit 
Explanation:
Here, we want to know the temperature after 9 hours 
Per hour rise each hour is 3/4 degree = 0.75 degree 
In 6 hours that will be 0.75 * 6 = 4.5 degrees 
Or hour drop is 1/4 = 0.25 degree
In 3 hours, that will be 0.25 * 3 = 0.75 degree 
Since it is a drop, we have -0.75 degree 
Temperature after 9 hours will be;
-5 + 4.5 -0.75
= -5.75 + 4.5 = -1.25 degrees fahrenheit