| x | − | x | ÷ | 21 20 | × | 1 20 | − | x | ÷ | 21 20 | × | 1 20 | × | 3 25 | − | x | × | 1 2000 | − | ( | x | − | x | ÷ | 21 20 | × | 1 20 | ) | × | 5 100 | = | 4500 |
| 方程左边 = | x | − | x | × | 1 21 | − | x | × | 1 175 | − | x | × | 1 2000 | − | ( | x | − | x | ÷ | 21 20 | × | 1 20 | ) | × | 5 100 |
| = | 5677 6000 | x | − | ( | x | − | x | ÷ | 21 20 | × | 1 20 | ) | × | 5 100 |
5677 6000 | x | − | ( | x | − | x | ÷ | 21 20 | × | 1 20 | ) | × | 5 100 | = | 4500 |
| 方程左边 = | 5677 6000 | x | − | x | × | 5 100 | + | x | ÷ | 21 20 | × | 1 20 | × | 5 100 |
| = | 5677 6000 | x | − | x | × | 5 100 | + | x | × | 1 420 |
| = | 37739 42000 | x |
37739 42000 | x | = | 4500 |
| x | = | 4500 | ÷ | 37739 42000 |
| = | 4500 | × | 42000 37739 |
| x | = | 189000000 37739 |
| x | = | 5008.081825 |