Explanation:
TYhe vertex of this parabola would be the minimum point....this could be found by graphing..... or use the Quadratic formula to find the zeroes....
the minumum is exactly in the middle of them
a = 1.2 b = - 216 c = 27 616
Plugging into the Quad Formula results in x = 90 +- 122.12 i
exactly in the middle is x = 90 machines