| X | − | 550 | − | ( | 100 | × | 6 100 | ÷ | 12 | + | 1500 | × | 8 100 | ÷ | 12 | + | X | × | 6 100 | ÷ | 12 | ) | = | 50 |
| Left side of the equation = | X | − | 550 | − | 100 | × | 6 100 | ÷ | 12 | − | 1500 | × | 8 100 | ÷ | 12 | − | X | × | 6 100 | ÷ | 12 |
| = | X | − | 550 | − | 1 2 | − | 10 | − | X | × | 1 200 |
| = | 199 200 | X | − | 1121 2 |
199 200 | X | − | 1121 2 | = | 50 |
199 200 | X | = | 50 | + | 1121 2 |
199 200 | X | = | 1221 2 |
| X | = | 1221 2 | ÷ | 199 200 |
| = | 1221 2 | × | 200 199 |
| = | 1221 | × | 100 199 |
| X | = | 122100 199 |
| X | = | 613.567839 |