G(x)=-x+0. Any equation reflected across the x axis will have the opposite x value as the original function. Hope this helps!
(f(x) in red, g(x) in blue)
P=(15x-2+4x+7)2=(19x+5)2=38x+10
Just divide the number of parts made by the number of hours to get parts per hour. 15 minutes is 1/4 of an hour, so we divide 360 by 0.25 hours: