Replace two wrenches with single equivalent wrench, find resultant and pitch

[physicsss]

Two bolts A and B are tightened by applying the forces and couple shown. replace the two wrenches with a single equivalent wrench and determine (a) the resultant, (b) the pitch of the single equivalent wrench (c), the point where the axis of the wrench intersects the xz plane.

 

[physicsss]

Does anyone know how to add two wrenches pictured above?