| 4500000 | × | 1 4 | = | 50000 | x | ( | 1 | − | 1 20 | ) | − | 4500000 |
| 方程左边 = | 1125000 |
| 1125000 | = | 50000 | x | ( | 1 | − | 1 20 | ) | − | 4500000 |
| 方程右边 = | 50000 | x | × | 1 | − | 50000 | x | × | 1 20 | − | 4500000 |
| = | 50000 | x | − | 2500 | x | − | 4500000 |
| = | 47500 | x | − | 4500000 |
| 1125000 | = | 47500 | x | − | 4500000 |
| - | 47500 | x | = | - | 4500000 | − | 1125000 |
| - | 47500 | x | = | - | 5625000 |
| 5625000 | = | 47500 | x |
| 47500 | x | = | 5625000 |
| x | = | 5625000 | ÷ | 47500 |
| = | 5625000 | × | 1 47500 |
| = | 2250 | × | 1 19 |
| x | = | 2250 19 |
| x | = | 118.421053 |