| 1000 | − | 4 | P | = | 200 | + | 2 | ( | P | − | 50 | ) |
| Right side of the equation = | 200 | + | 2 | P | − | 2 | × | 50 |
| = | 200 | + | 2 | P | − | 100 |
| = | 100 | + | 2 | P |
| 1000 | − | 4 | P | = | 100 | + | 2 | P |
| - | 4 | P | − | 2 | P | = | 100 | − | 1000 |
| - | 6 | P | = | 100 | − | 1000 |
| - | 6 | P | = | - | 900 |
| 900 | = | 6 | P |
| 6 | P | = | 900 |
| P | = | 900 | ÷ | 6 |
| = | 900 | × | 1 6 |
| = | 150 | × | 1 |
| P | = | 150 |