| 2100 | ( | x | − | 20 | ) | = | 460 | × | 1 2 | ( | 81 | − | x | ) |
| 方程左边 = | 2100 | x | − | 2100 | × | 20 |
| = | 2100 | x | − | 42000 |
| 2100 | x | − | 42000 | = | 460 | × | 1 2 | ( | 81 | − | x | ) |
| 方程右边 = | 230 | ( | 81 | − | x | ) |
| 2100 | x | − | 42000 | = | 230 | ( | 81 | − | x | ) |
| 方程右边 = | 230 | × | 81 | − | 230 | x |
| = | 18630 | − | 230 | x |
| 2100 | x | − | 42000 | = | 18630 | − | 230 | x |
| 2100 | x | + | 230 | x | = | 18630 | + | 42000 |
| 2330 | x | = | 18630 | + | 42000 |
| 2330 | x | = | 60630 |
| x | = | 60630 | ÷ | 2330 |
| = | 60630 | × | 1 2330 |
| = | 6063 | × | 1 233 |
| x | = | 6063 233 |
| x | = | 26.021459 |