| x | ÷ | ( | 1 40 | − | x | ) | = | 19 1000 |
| 方程两边同时乘以: | ( | 1 40 | − | x | ) |
| x | = | 19 1000 | ( | 1 40 | − | x | ) |
| x | = | 19 1000 | × | 1 40 | − | 19 1000 | x |
| x | = | 19 40000 | − | 19 1000 | x |
| x | + | 19 1000 | x | = | 19 40000 |
1019 1000 | x | = | 19 40000 |
| x | = | 19 40000 | ÷ | 1019 1000 |
| = | 19 40000 | × | 1000 1019 |
| = | 19 40 | × | 1 1019 |
| x | = | 19 40760 |
| x | = | 0.000466 |