| ( | x | + | 15000 | ) | × | 9 5 | + | ( | ( | ( | x | + | 15000 | ) | × | 9 5 | ) | × | 9 5 | ) | = | 73021 |
| 方程左边 = | x | × | 9 5 | + | 15000 | × | 9 5 | + | ( | ( | ( | x | + | 15000 | ) | × | 9 5 | ) | × | 9 5 | ) |
| = | x | × | 9 5 | + | 27000 | + | ( | ( | ( | x | + | 15000 | ) | × | 9 5 | ) | × | 9 5 | ) |
| = | 9 5 | x | + | 27000 | + | ( | ( | x | + | 15000 | ) | × | 9 5 | ) | × | 9 5 |
| = | 9 5 | x | + | 27000 | + | ( | x | + | 15000 | ) | × | 9 5 | × | 9 5 |
| = | 9 5 | x | + | 27000 | + | ( | x | + | 15000 | ) | × | 81 25 |
| = | 9 5 | x | + | 27000 | + | x | × | 81 25 | + | 15000 | × | 81 25 |
| = | 9 5 | x | + | 27000 | + | x | × | 81 25 | + | 48600 |
| = | 126 25 | x | + | 75600 |
126 25 | x | + | 75600 | = | 73021 |
126 25 | x | = | 73021 | − | 75600 |
126 25 | x | = | - | 2579 |
| x | = | - | 2579 | ÷ | 126 25 |
| = | - | 2579 | × | 25 126 |
| x | = | - | 64475 126 |
| x | = | - 511.706349 |