Equivalent force System:
An equivalent system for the given system of coplanar forces is the combination of force passing through given point and moment about that point. The force is resultant of all the forces acting on the body. And the moment is sum of all the moments about that point.
Thus equivalent system consists of:
1. A single force R passing through given point, and
2. A single moment (ΣM) Where,
R = resultant of all the force acting on body
ΣM = Sum of all the moments of all the forces about P.