| x | × | 4 | − | 125 | x | × | 2 | − | 40 | x | + | 100 | + | 642 | = | 0 |
| Left side of the equation = | x | × | 4 | − | 250 | x | − | 40 | x | + | 100 | + | 642 |
| = | - | 286 | x | + | 742 |
| - | 286 | x | + | 742 | = | 0 |
| - | 286 | x | = | 0 | − | 742 |
| - | 286 | x | = | - | 742 |
| 742 | = | 286 | x |
| 286 | x | = | 742 |
| x | = | 742 | ÷ | 286 |
| = | 742 | × | 1 286 |
| = | 371 | × | 1 143 |
| x | = | 371 143 |
| x | = | 2.594406 |