The temperature was -13F and then rose 9F the addition expression that represents the final temperature

Answer question above and explain each step : )

The architect's side view drawing of a saltbox-style house shows a post that supports the roof ridge. the support post is 8 ft tall. the distance from the front of the house to the support post is less than the distance from the post to the back of the house. how far from the front of the house is the support post positioned?

Describe how to determine the average rate of change between x = 4 and x = 6 for the function f(x) = 2x^3 + 4. include the average rate of change in your answer.