Answer:
The percent decrease is approximately 
(Don't know what you are expected to round to.)
Step-by-step explanation:
Percent change can be calculated by doing:

Then you multiply the result to covert it to a percentage.
Let's use this formula:




approximately
Now the answer as a percent is
approximately.
The percent decrease is approximately 
The domain is the set of possible inputs, i.e. the x-coordinates of the points.
Here those are 6, 1 and - 3 which in order is -3, 1, 6.
Then the answer is {-3, 1, 6}.
By the way note that this relation is not a function. Do you know why?
Because the image of -3 is not stated unambiguosly.
Answer:
Chile all 10 QuEsTiOns. My brain died.
Answer:
Hey, where is the circle? I think you forgot to upload pic of circle.