The three forces acting on the beam can be replaced with a single equivalent force R. Determine the angle θ and R. I was able to come up with the below equations but after the last one, regarding the moment of resultant, I got stuck. 

Fx = 25kNcos(40) + 60kNcos(θ) - 80kNcos(50)

Fy = 25kNsin(40) + 60kNsin(θ) + 80kNsin(50)

∑Mo = Rd

[Moment at P2 point.]

Rd = -25sin(40)(4) + 80sin(50)(6)
Solve for theta first then solve sum of Fx and Fy:
Solve for theta first then solve sum of Fx and Fy: