D6976 Each additional cast post - same tooth - To be used with D6970 or D6971. D6977 Each additional prefabricated post - same tooth - To be used with D6972. D6980 Fixed partial denture repair, by report. D6985 Pediatric partial denture, fixed - This prosthesis is used primarily for aesthetic purposes.
This method can be described as follows: 1  In the first equation, solve for one of the variables in terms of the others. 2  Substitute this expression into the remaining equations. This yields a system of equations with one fewer equation and one fewer unknown. 3  Repeat until the system is reduced to a single linear equation.
The graph of a system of two linear equations produces three scenarios: 1  The lines have one point of intersection. This is the only solution of the system. 2  The lines are parallel and there is no point that satisfies both equations. The system has no solution.