| 80 | − | x | = | ( | 2150 | − | 25 | x | ) | ÷ | 28 |
| Right side of the equation = | 2150 | × | 1 28 | − | 25 | x | × | 1 28 |
| = | 1075 14 | − | 25 28 | x |
| 80 | − | x | = | 1075 14 | − | 25 28 | x |
| - | x | + | 25 28 | x | = | 1075 14 | − | 80 |
| - | 3 28 | x | = | 1075 14 | − | 80 |
| - | 3 28 | x | = | - | 45 14 |
45 14 | = | 3 28 | x |
3 28 | x | = | 45 14 |
| x | = | 45 14 | ÷ | 3 28 |
| = | 45 14 | × | 28 3 |
| = | 15 | × | 2 |
| x | = | 30 |