| ( | 500 | − | X | ) | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X | = | 500 | ( | 1 | + | 136 500 | ) |
| 方程左边 = | 500 | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 500 | × | 1 | ( | 1 | − | 40 100 | ) | X | + | 500 | × | 30 100 | ( | 1 | − | 40 100 | ) | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 500 | ( | 1 | − | 40 100 | ) | X | + | 150 | ( | 1 | − | 40 100 | ) | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 500 | × | 1 | X | − | 500 | × | 40 100 | X | + | 150 | ( | 1 | − | 40 100 | ) | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) |
| = | 500 | X | − | 200 | X | + | 150 | ( | 1 | − | 40 100 | ) | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 300 | X | + | 150 | ( | 1 | − | 40 100 | ) | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 300 | X | + | 150 | × | 1 | X | − | 150 | × | 40 100 | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 300 | X | + | 150 | X | − | 60 | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 390 | X | − | X | ( | 1 | + | 30 100 | ) | ( | 1 | − | 40 100 | ) | X |
| = | 390 | X | − | X | × | 1 | ( | 1 | − | 40 100 | ) | X | − | X | × | 30 100 | ( | 1 | − | 40 100 | ) | X |
| = | 390 | X | − | X | × | 1 | × | 1 | X | + | X | × | 1 | × | 40 100 | X | − | X | × | 30 100 |
| = | 390 | X | − | X | × | 1 | X | + | X | × | 2 5 | X | − | X | × | 30 100 | ( | 1 | − | 40 100 | ) | X |
| = | 390 | X | − | X | × | 1 | X | + | X | × | 2 5 | X | − | X | × | 30 100 | × | 1 | X |
| = | 390 | X | − | X | × | 1 | X | + | X | × | 2 5 | X | − | X | × | 3 10 | X | + | X |
| 390 | X | − | X | × | 1 | X | + | X | × | 2 5 | X | − | X | × | 3 10 | X | + | X | = | 500 | ( | 1 | + | 136 500 | ) |
| 方程右边 = | 500 | × | 1 | + | 500 | × | 136 500 |
| = | 500 | + | 136 |
| = | 636 |
| 390 | X | − | X | × | 1 | X | + | X | × | 2 5 | X | − | X | × | 3 10 | X | + | X | = | 636 |