| 500000 | x | − | 300 | − | 500000 | × | 80 | − | 500000 | × | 5 | = | 0 |
| 方程左边 = | 500000 | x | − | 300 | − | 40000000 | − | 2500000 |
| = | 500000 | x | − | 42500300 |
| 500000 | x | − | 42500300 | = | 0 |
| 500000 | x | = | 0 | + | 42500300 |
| 500000 | x | = | 42500300 |
| x | = | 42500300 | ÷ | 500000 |
| = | 42500300 | × | 1 500000 |
| = | 425003 | × | 1 5000 |
| x | = | 425003 5000 |
| x | = | 85.0006 |