| 10 | x | = | 125 | + | 25 | ( | x | − | 11 2 | − | 10 | ) |
| Right side of the equation = | 125 | + | 25 | x | − | 25 | × | 11 2 | − | 25 | × | 10 |
| = | 125 | + | 25 | x | − | 275 2 | − | 250 |
| = | - | 525 2 | + | 25 | x |
| 10 | x | = | - | 525 2 | + | 25 | x |
| 10 | x | − | 25 | x | = | - | 525 2 |
| - | 15 | x | = | - | 525 2 |
525 2 | = | 15 | x |
| 15 | x | = | 525 2 |
| x | = | 525 2 | ÷ | 15 |
| = | 525 2 | × | 1 15 |
| = | 35 2 | × | 1 |
| x | = | 35 2 |
| x | = | 17.5 |