The slope would be:
-5--3/3-1
-2/2
-1
Slope = -1
It’s 45%
Explanation = 31900-22000/22000 • 100 = 45%
For the first one his car used 8/340 or 2/85 gallons for one mile.
After the fix, his car 7/350 or 1/50 gallons for one mile.
Then you subtract 1/50-2/85 to get (17-10)/850 or 7/850.
You multiply this by 4 to get 28/850 which is $0.0329411
Since it is asking for cents you multiply by 100 to get approximately 3 cents.
For this case we have the following functions:

We must subtract the functions:

We build a table of values for 

Answer:

That was made up?cz I tried to solve it and I kept getting different #s