| 1000 | ÷ | x | = | 1000 | ÷ | ( | 5 4 | x | ) | + | 40 |
| 方程两边同时乘以: | x | , | ( | 5 4 | × | 1 | ) |
| 1000 | ( | 5 4 | × | 1 | ) | = | 1000 | × | 1 | + | 40 | x | ( | 5 4 | × | 1 | ) |
| 1000 | × | 5 4 | × | 1 | = | 1000 | × | 1 | + | 40 | x | ( | 5 4 | × | 1 | ) |
| 1000 | × | 5 4 | × | 1 | = | 1000 | × | 1 | + | 40 | x | × | 5 4 | × | 1 |
| 1250 | = | 1000 | + | 50 | x |
| - | 50 | x | = | 1000 | − | 1250 |
| - | 50 | x | = | - | 250 |
| 250 | = | 50 | x |
| 50 | x | = | 250 |
| x | = | 250 | ÷ | 50 |
| = | 250 | × | 1 50 |
| = | 5 | × | 1 |
| x | = | 5 |