| 10000 | + | 9000 | x | × | 5 | + | 8500 | x | × | 4 | + | 8000 | x | × | 3 | + | 7000 | x | = | 0 |
| 方程左边 = | 10000 | + | 45000 | x | + | 34000 | x | + | 24000 | x | + | 28000 | x | + | 13000 | x |
| = | 10000 | + | 144000 | x |
| 10000 | + | 144000 | x | = | 0 |
| 144000 | x | = | 0 | − | 10000 |
| 144000 | x | = | - | 10000 |
| x | = | - | 10000 | ÷ | 144000 |
| = | - | 10000 | × | 1 144000 |
| = | - | 5 | × | 1 72 |
| x | = | - | 5 72 |
| x | = | - 0.069444 |