| ( | x | − | 1280 | ) | ÷ | 5280 | = | ( | x | − | 2000 | ) | ÷ | 4000 |
| Left side of the equation = | x | × | 1 5280 | − | 1280 | × | 1 5280 |
| = | x | × | 1 5280 | − | 8 33 |
1 5280 | x | − | 8 33 | = | ( | x | − | 2000 | ) | ÷ | 4000 |
| Right side of the equation = | x | × | 1 4000 | − | 2000 | × | 1 4000 |
| = | x | × | 1 4000 | − | 1 2 |
1 5280 | x | − | 8 33 | = | 1 4000 | x | − | 1 2 |
1 5280 | x | − | 1 4000 | x | = | - | 1 2 | + | 8 33 |
| - | 1 16500 | x | = | - | 1 2 | + | 8 33 |
| - | 1 16500 | x | = | - | 17 66 |
17 66 | = | 1 16500 | x |
1 16500 | x | = | 17 66 |
| x | = | 17 66 | ÷ | 1 16500 |
| = | 17 66 | × | 16500 |
| = | 17 | × | 250 |
| x | = | 4250 |