Sherman Corporation distributes its service department overhead costs directly to producing departments without allocation to the other service departments. Information for March is presented here. 

      Maintenance Utilities Overhead costs incurred $18,700 $9,000

  Service provided to:       

Maintenance Dept.   10%

Utilities Dept. 20%

Producing Dept. A 40% 30%

Producing Dept. B   40%  60%

Refer to Sherman Corporation. Assume that Sherman Corporation distributes service department overhead costs based on the algebraic method. What would be the formula to determine the total maintenance costs?