| 3000 | × | 1 200 | + | ( | 5000 | − | 3000 | ) | × | 1 100 | + | ( | 10000 | − | 5000 | ) | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 | = | 333 |
| 方程左边 = | 15 | + | ( | 5000 | − | 3000 | ) | × | 1 100 | + | ( | 10000 | − | 5000 | ) | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 |
| 15 | + | ( | 5000 | − | 3000 | ) | × | 1 100 | + | ( | 10000 | − | 5000 | ) | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 | = | 333 |
| 方程左边 = | 15 | + | 5000 | × | 1 100 | − | 3000 | × | 1 100 | + | ( | 10000 | − | 5000 | ) | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 |
| = | 15 | + | 50 | − | 30 | + | ( | 10000 | − | 5000 | ) | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 |
| = | 35 | + | ( | 10000 | − | 5000 | ) | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 |
| = | 35 | + | 10000 | × | 3 200 | − | 5000 | × | 3 200 | + | ( | x | − | 10000 | ) | × | 2 100 |
| = | 35 | + | 150 | − | 75 | + | ( | x | − | 10000 | ) | × | 2 100 |
| = | 110 | + | ( | x | − | 10000 | ) | × | 2 100 |
| = | 110 | + | x | × | 2 100 | − | 10000 | × | 2 100 |
| = | 110 | + | x | × | 2 100 | − | 200 |
| = | - | 90 | + | 2 100 | x |
| - | 90 | + | 2 100 | x | = | 333 |
2 100 | x | = | 333 | + | 90 |
2 100 | x | = | 423 |
| x | = | 423 | ÷ | 2 100 |
| = | 423 | × | 100 2 |
| x | = | 42300 2 |
| x | = | 21150 |