I have no idea if I am doing this right or exactly where to start. Moments keep confusing the hell out of me, its so frustrating. So far for part A I got the

resultant moment = -1200(sin x + cos x)

To get part A i took the cross product of the vector components of the distance between each force and A and the components of the force itself. Like this

M1 = r x F = (-3i + 2j) x (400cosx i + 400sinx j) = (-1200sinx - 800cosx) k

M2 = r x F = (0i + 1j) x (400cosx i + 400sinx j) = (-400cosx) k

Meq = (-1200sinx - 800cosx - 400cosx) k =-1200(sinx + cosx)

Umm so am i allowed to do this?

Is this correct and can someone guide me with the other parts of the problem?

Also one part that was left out of the drawing is that the distance from A to B is 1m