| 2 | x | × | 30 | + | x | × | 80 | + | ( | 5200 | − | 3 | x | ) | × | 50 | = | 255000 |
| Left side of the equation = | 60 | x | + | x | × | 80 | + | ( | 5200 | − | 3 | x | ) | × | 50 |
| = | 140 | x | + | ( | 5200 | − | 3 | x | ) | × | 50 |
| 140 | x | + | ( | 5200 | − | 3 | x | ) | × | 50 | = | 255000 |
| Left side of the equation = | 140 | x | + | 5200 | × | 50 | − | 3 | x | × | 50 |
| = | 140 | x | + | 260000 | − | 150 | x |
| = | - | 10 | x | + | 260000 |
| - | 10 | x | + | 260000 | = | 255000 |
| - | 10 | x | = | 255000 | − | 260000 |
| - | 10 | x | = | - | 5000 |
| 5000 | = | 10 | x |
| 10 | x | = | 5000 |
| x | = | 5000 | ÷ | 10 |
| = | 5000 | × | 1 10 |
| = | 500 | × | 1 |
| x | = | 500 |