| ( | 85 | ( | 1 | + | 20 100 | ) | ) | + | ( | 8 100 | x | ) | = | x |
| 方程左边 = | 85 | ( | 1 | + | 20 100 | ) | + | ( | 8 100 | x | ) |
| = | 85 | × | 1 | + | 85 | × | 20 100 | + | ( | 8 100 | x | ) |
| = | 85 | + | 17 | + | ( | 8 100 | x | ) |
| = | 102 | + | ( | 8 100 | x | ) |
| = | 102 | + | 8 100 | x |
| 102 | + | 8 100 | x | = | x |
8 100 | x | − | x | = | - | 102 |
| - | 23 25 | x | = | - | 102 |
| 102 | = | 23 25 | x |
23 25 | x | = | 102 |
| x | = | 102 | ÷ | 23 25 |
| = | 102 | × | 25 23 |
| x | = | 2550 23 |
| x | = | 110.869565 |