| 20 | + | ( | x | × | 51 50 | + | 5 2 | ) | + | 3 20 | x | + | ( | 20 | × | 331 2000 | ) | = | 0 |
| 方程左边 = | 20 | + | x | × | 51 50 | + | 5 2 | + | 3 20 | x | + | ( | 20 | × | 331 2000 | ) |
| = | 45 2 | + | 117 100 | x | + | ( | 20 | × | 331 2000 | ) |
| = | 45 2 | + | 117 100 | x | + | 20 | × | 331 2000 |
| = | 45 2 | + | 117 100 | x | + | 331 100 |
| = | 2581 100 | + | 117 100 | x |
2581 100 | + | 117 100 | x | = | 0 |
117 100 | x | = | 0 | − | 2581 100 |
117 100 | x | = | - | 2581 100 |
| x | = | - | 2581 100 | ÷ | 117 100 |
| = | - | 2581 100 | × | 100 117 |
| = | - | 2581 | × | 1 117 |
| x | = | - | 2581 117 |
| x | = | - 22.059829 |