| Y | = | ( | 1000 | + | 4 5 | ( | Y | − | 200 | − | 1 4 | Y | + | 400 | ) | ) | + | 2000 | + | 2500 |
| 方程右边 = | ( | 1000 | + | 4 5 | ( | Y | − | 200 | − | 1 4 | Y | + | 400 | ) | ) | + | 4500 |
| Y | = | ( | 1000 | + | 4 5 | ( | Y | − | 200 | − | 1 4 | Y | + | 400 | ) | ) | + | 4500 |
| 方程右边 = | 1000 | + | 4 5 | ( | Y | − | 200 | − | 1 4 | Y | + | 400 | ) | + | 4500 |
| = | 5500 | + | 4 5 | ( | Y | − | 200 | − | 1 4 | Y | + | 400 | ) |
| = | 5500 | + | 4 5 | Y | − | 4 5 | × | 200 | − | 4 5 | × | 1 4 | Y | + | 4 5 | × | 400 |
| = | 5500 | + | 4 5 | Y | − | 160 | − | 1 5 | Y | + | 320 |
| = | 5660 | + | 3 5 | Y |
| Y | = | 5660 | + | 3 5 | Y |
| Y | − | 3 5 | Y | = | 5660 |
2 5 | Y | = | 5660 |
| Y | = | 5660 | ÷ | 2 5 |
| = | 5660 | × | 5 2 |
| = | 2830 | × | 5 |
| Y | = | 14150 |