13 100 | x | + | ( | x | × | 21 20 | + | 30 | ) | + | 3 20 | x | + | ( | 13 100 | x | × | 331 2000 | ) | = | 297641 100 |
| 方程左边 = | 7 25 | x | + | ( | x | × | 21 20 | + | 30 | ) | + | ( | 13 100 | x | × | 331 2000 | ) |
7 25 | x | + | ( | x | × | 21 20 | + | 30 | ) | + | ( | 13 100 | x | × | 331 2000 | ) | = | 297641 100 |
| 方程左边 = | 7 25 | x | + | x | × | 21 20 | + | 30 | + | ( | 13 100 | x | × | 331 2000 | ) |
| = | 133 100 | x | + | 30 | + | ( | 13 100 | x | × | 331 2000 | ) |
| = | 133 100 | x | + | 30 | + | 13 100 | x | × | 331 2000 |
| = | 133 100 | x | + | 30 | + | 4303 200000 | x |
| = | 270303 200000 | x | + | 30 |
270303 200000 | x | + | 30 | = | 297641 100 |
270303 200000 | x | = | 297641 100 | − | 30 |
270303 200000 | x | = | 294641 100 |
| x | = | 294641 100 | ÷ | 270303 200000 |
| = | 294641 100 | × | 200000 270303 |
| = | 294641 | × | 2000 270303 |
| x | = | 589282000 270303 |
| x | = | 2180.079392 |