The answer is -3
-12c = 43 - 7
-12c = 36
÷ -12 ÷-12
c = -3
It’s volume / designation
I believe the sum of the interior angles is the number of sides (n), subtracted by 2, and multiplied by 180.
(n - 2) x 180 = sum of interior angles of a n-gon
I also believe that the sum of exterior angles of a n-gon equals to 360 degrees.
2x - y = 0
2x = y
3x - 2(2x) = -3
3x - 4x = -3
-x = -3
x = 3
2(3) = y
6 = y