| ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | + | ( | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | ) | = | 73000 |
| 方程左边 = | x | + | 15000 | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | + | ( | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | ) |
| = | x | + | 15000 | + | ( | x | + | 15000 | ) | × | 4 5 | + | ( | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | ) |
| = | x | + | 15000 | + | x | × | 4 5 | + | 15000 | × | 4 5 | + | ( | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | ) |
| = | x | + | 15000 | + | x | × | 4 5 | + | 12000 | + | ( | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | ) |
| = | 9 5 | x | + | 27000 | + | ( | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) | ) |
| = | 9 5 | x | + | 27000 | + | ( | x | + | 15000 | ) | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) |
| = | 9 5 | x | + | 27000 | + | x | + | 15000 | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) |
| = | 14 5 | x | + | 42000 | + | ( | ( | x | + | 15000 | ) | × | 4 5 | ) |
| = | 14 5 | x | + | 42000 | + | ( | x | + | 15000 | ) | × | 4 5 |
| = | 14 5 | x | + | 42000 | + | x | × | 4 5 | + | 15000 | × | 4 5 |
| = | 14 5 | x | + | 42000 | + | x | × | 4 5 | + | 12000 |
| = | 18 5 | x | + | 54000 |
18 5 | x | + | 54000 | = | 73000 |
18 5 | x | = | 73000 | − | 54000 |
18 5 | x | = | 19000 |
| x | = | 19000 | ÷ | 18 5 |
| = | 19000 | × | 5 18 |
| = | 9500 | × | 5 9 |
| x | = | 47500 9 |
| x | = | 5277.777778 |