Well from what i know here's what i would put........
-4 * -2 = 8 - 2 = 6
-4 * -1 = 4 - 2 = 2
-4 * 0 = 0 - 2 = -2
so it does represent a function......I really hope that helped!!
Knowing the interior angle sum formula is;
180x(n-2)
180x(n-2)=1260 (solve for n here)
180n-360=1260
180n=1260+360
180n=1620
n=1620/180
n=9
Therefore, this polygon has 9 sides.
Hope I helped :)
2 1/10 because the 1 in 2.1 is in the tenth place