The following is a system of simultaneous linear equations to allocate costs using the reciprocal method. Matrix algebra is not required The following costs were incurred in three operating departments and three service departments in Westmoreland Company Department Direct Costs Label Subassemblies $550,000 P1 Final assembly 775,000 P2 Marketing 285,000 P3 Building occupancy 85,000 $1 Research & development 120,000 52 Supervision 45,000 53 Use of services by other departments is as follows User Departments Sub- Service Cost Center: assemblies. Final Assembly Marketing Building Occupancy R&D Supervision Building occupancy 0.30 0.25 0.20 0.15 0.10 R&D 0.50 0.50 Supervision 0.20 0:30 0.20 0.10 0.20 The equation for department S3 (supervision) is