| 100 | × | 49 5 | + | x | × | 491 | = | ( | 100 | + | x | ) | × | 25 |
| 方程左边 = | 980 | + | x | × | 491 |
| 980 | + | 491 | x | = | ( | 100 | + | x | ) | × | 25 |
| 方程右边 = | 100 | × | 25 | + | x | × | 25 |
| = | 2500 | + | x | × | 25 |
| 980 | + | 491 | x | = | 2500 | + | 25 | x |
| 491 | x | − | 25 | x | = | 2500 | − | 980 |
| 466 | x | = | 2500 | − | 980 |
| 466 | x | = | 1520 |
| x | = | 1520 | ÷ | 466 |
| = | 1520 | × | 1 466 |
| = | 760 | × | 1 233 |
| x | = | 760 233 |
| x | = | 3.261803 |