Answer:
18,646
Explanation:
>you can graph the equation on a calculator and see that the minimum is at the point (250, 18646) , so the minimum unit cost is 18,646
>you can use the first derivative to find the minimum
c'(x) = (0.2x²-100x+31,146)' = .4x -100
.4x-100= 0 , so x= 250
c(x=250) = 0.2(250)² -100*250 +31,146 =18,646