| ( | 2 | x | × | 70 | + | 3 | x | × | 30 | + | ( | 12 5 | ) | x | × | 80 | + | ( | 18 5 | ) | x | × | 40 | ) | × | 9 10 | = | 30286 |
| 方程左边 = | 2 | x | × | 70 | × | 9 10 | + | 3 | x | × | 30 | × | 9 10 | + | ( | 12 5 | ) | x | × | 80 | × | 9 10 |
| = | 126 | x | + | 81 | x | + | ( | 12 5 | ) | x | × | 72 | + | ( | 18 5 | ) | x | × | 36 |
| = | 207 | x | + | ( | 12 5 | ) | x | × | 72 | + | ( | 18 5 | ) | x | × | 36 |
| = | 207 | x | + | 12 5 | x | × | 72 | + | ( | 18 5 | ) | x | × | 36 |
| = | 207 | x | + | 864 5 | x | + | ( | 18 5 | ) | x | × | 36 |
| = | 1899 5 | x | + | ( | 18 5 | ) | x | × | 36 |
| = | 1899 5 | x | + | 18 5 | x | × | 36 |
| = | 1899 5 | x | + | 648 5 | x |
| = | 2547 5 | x |
2547 5 | x | = | 30286 |
| x | = | 30286 | ÷ | 2547 5 |
| = | 30286 | × | 5 2547 |
| x | = | 151430 2547 |
| x | = | 59.45426 |