| 0 | = | y | × | 500000 | − | 80 | × | 500000 | − | 3000000 | − | 5 | × | 500000 |
| 方程右边 = | y | × | 500000 | − | 40000000 | − | 3000000 | − | 2500000 |
| = | 500000 | y | − | 45500000 |
| 0 | = | 500000 | y | − | 45500000 |
| - | 500000 | y | = | - | 45500000 | − | 0 |
| - | 500000 | y | = | - | 45500000 |
| 45500000 | = | 500000 | y |
| 500000 | y | = | 45500000 |
| y | = | 45500000 | ÷ | 500000 |
| = | 45500000 | × | 1 500000 |
| = | 91 | × | 1 |
| y | = | 91 |