If you are looking for the equation, then it would be y = -x+3
This is the same as y = -1x+3 which is in slope intercept form y = mx+b
m = -1 = slope
b = 3 = y intercept
If you want to graph this, then plot the points (0,3) and (1,2). Then draw a straight line through them both. Extend the line in both directions as much as possible.
The answer will be a because if you add 70 +98+83+66+41 divided by 5 is 325.2 and I'd u add 81 and divide it by 6 then it will equal 371.5 so it will increase