| 5 | ( | 10 | + | 1 4 | x | ) | × | 100 | + | x | = | 0 |
| 方程左边 = | 500 | ( | 10 | + | 1 4 | x | ) | + | x |
| 500 | ( | 10 | + | 1 4 | x | ) | + | x | = | 0 |
| 方程左边 = | 500 | × | 10 | + | 500 | × | 1 4 | x | + | x |
| = | 5000 | + | 125 | x | + | x |
| = | 5000 | + | 126 | x |
| 5000 | + | 126 | x | = | 0 |
| 126 | x | = | 0 | − | 5000 |
| 126 | x | = | - | 5000 |
| x | = | - | 5000 | ÷ | 126 |
| = | - | 5000 | × | 1 126 |
| = | - | 2500 | × | 1 63 |
| x | = | - | 2500 63 |
| x | = | - 39.68254 |