| 2000 | − | 1600 | ( | 50 | − | 40 | ) | + | 40 | x | = | 50 | x |
| Left side of the equation = | 2000 | − | 1600 | × | 50 | + | 1600 | × | 40 | + | 40 | x |
| = | 2000 | − | 80000 | + | 64000 | + | 40 | x |
| = | - | 14000 | + | 40 | x |
| - | 14000 | + | 40 | x | = | 50 | x |
| 40 | x | − | 50 | x | = | 14000 |
| - | 10 | x | = | 14000 |
| - | 14000 | = | 10 | x |
| 10 | x | = | - | 14000 |
| x | = | - | 14000 | ÷ | 10 |
| = | - | 14000 | × | 1 10 |
| = | - | 1400 | × | 1 |
| x | = | - | 1400 |