1)
n 1 2 3 4 5 6
f(n) 1033 932 831 730 629 528
First term (a₁): <u>1033 </u> Common difference (d): <u>-101 </u>
Explicit rule:
Recursive rule: 




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2)
n 1 2 3 4 5 6
f(n) -39 -29 -19 -9 9 19
First term (a₁): <u> -39 </u> Common difference (d): <u> +10 </u>
Explicit rule:
Recursive rule: 




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3)
n 1 2 3 4 5 6
f(n) 3.75 2.5 1.25 0 -1.25 -2.5
First term (a₁): <u> 3.75 </u> Common difference (d): <u> -1.25 </u>
Explicit rule:
Recursive rule: 




Round 358 to the nearest 5 or 10, which would be 360. 360/3=120 so the compatible number would be 120.
The graph is wrong, the slope is correct but because the sign is less than y that means the line on the graph should be dotted not solid.
Let us have a recap first.
For triangle it's 180 degrees in total
Square has 360 degrees in total
Pentagon has 540 degrees total
Hexagon has 720 degrees in total
So these polygons increase by 180 degrees for every side to the polygon starting at three sides instead of one.
Let:
n = number of sides in the polygon
(n-2) * 180 = degrees total inside the polygon
(n-2) * 180 / n = degrees for each angle in polygon
Substitute:
(n-2) * 180 / n = 162
multiply both sides by n
(n-2) * 180 = 162n
then divide both sides by 180
n-2 = 162n / 180
n-2 = 0.9n
subtract 0.9n and add 2 to both sides to get n alone
0.1n = 2
n = 20 sides
Thus,
Icosagon (20-gon) is the term for a 20 sided polygon
I believe the only true one is B.