| 10 | x | × | 2 | − | 900 | x | + | 20000 | = | 8000 |
| Left side of the equation = | 20 | x | − | 900 | x | + | 20000 |
| = | - | 880 | x | + | 20000 |
| - | 880 | x | + | 20000 | = | 8000 |
| - | 880 | x | = | 8000 | − | 20000 |
| - | 880 | x | = | - | 12000 |
| 12000 | = | 880 | x |
| 880 | x | = | 12000 |
| x | = | 12000 | ÷ | 880 |
| = | 12000 | × | 1 880 |
| = | 150 | × | 1 11 |
| x | = | 150 11 |
| x | = | 13.636364 |