Replace the three forces acting on the plate by a wrench. Specify the magnitude of the force

Question:

Replace the three forces acting on the plate by a wrench. Specify the magnitude of the force and couple moment for the wrench and the point P(y, z) where its line of action intersects the plate.
Given:
FA = 80 lb a = 12 ft
FB = 60 lb b = 12 ft
FC = 40 lb