| ( | x | ÷ | 109 100 | × | 9 100 | − | x | ÷ | 109 100 | × | 1 1000 | ) | ÷ | 9 100 | × | 109 100 | = | 112 |
| 方程左边 = | ( | x | ÷ | 109 100 | × | 9 100 | − | x | ÷ | 109 100 | × | 1 1000 | ) | × | 109 9 |
| ( | x | ÷ | 109 100 | × | 9 100 | − | x | ÷ | 109 100 | × | 1 1000 | ) | × | 109 9 | = | 112 |
| 方程左边 = | x | ÷ | 109 100 | × | 9 100 | × | 109 9 | − | x | ÷ | 109 100 | × | 1 1000 | × | 109 9 |
| = | x | × | 1 | − | x | × | 1 90 |
| = | 89 90 | x |
89 90 | x | = | 112 |
| x | = | 112 | ÷ | 89 90 |
| = | 112 | × | 90 89 |
| x | = | 10080 89 |
| x | = | 113.258427 |