The following is a system of simultaneous inear 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. Use of services by other departments is as follows. The equation for department \$3 (supervision) is: The equaton for department S3 (supervision) is: Multiple Cholce $3=$59,000+0.15S1. S3=0.15Si. $3=$59,000+1,00S1 $3=$59.000+0.85S1+0.15S2