| ( | 389 | ( | 1 | + | 20 100 | ) | ) | + | ( | 7 100 | x | ) | = | x |
| 方程左边 = | 389 | ( | 1 | + | 20 100 | ) | + | ( | 7 100 | x | ) |
| = | 389 | × | 1 | + | 389 | × | 20 100 | + | ( | 7 100 | x | ) |
| = | 389 | + | 389 5 | + | ( | 7 100 | x | ) |
| = | 2334 5 | + | ( | 7 100 | x | ) |
| = | 2334 5 | + | 7 100 | x |
2334 5 | + | 7 100 | x | = | x |
7 100 | x | − | x | = | - | 2334 5 |
| - | 93 100 | x | = | - | 2334 5 |
2334 5 | = | 93 100 | x |
93 100 | x | = | 2334 5 |
| x | = | 2334 5 | ÷ | 93 100 |
| = | 2334 5 | × | 100 93 |
| = | 778 | × | 20 31 |
| x | = | 15560 31 |
| x | = | 501.935484 |