| Y | = | 300 | + | 3 5 | ( | Y | − | 1000 | ) | + | 1000 | + | 1300 |
| 方程右边 = | 2600 | + | 3 5 | ( | Y | − | 1000 | ) |
| Y | = | 2600 | + | 3 5 | ( | Y | − | 1000 | ) |
| 方程右边 = | 2600 | + | 3 5 | Y | − | 3 5 | × | 1000 |
| = | 2600 | + | 3 5 | Y | − | 600 |
| = | 2000 | + | 3 5 | Y |
| Y | = | 2000 | + | 3 5 | Y |
| Y | − | 3 5 | Y | = | 2000 |
2 5 | Y | = | 2000 |
| Y | = | 2000 | ÷ | 2 5 |
| = | 2000 | × | 5 2 |
| = | 1000 | × | 5 |
| Y | = | 5000 |