| 10000 | ( | 1 | + | x | ) | × | 2 | = | 50 |
| Left side of the equation = | 20000 | ( | 1 | + | x | ) |
| 20000 | ( | 1 | + | x | ) | = | 50 |
| Left side of the equation = | 20000 | × | 1 | + | 20000 | x |
| = | 20000 | + | 20000 | x |
| 20000 | + | 20000 | x | = | 50 |
| 20000 | x | = | 50 | − | 20000 |
| 20000 | x | = | - | 19950 |
| x | = | - | 19950 | ÷ | 20000 |
| = | - | 19950 | × | 1 20000 |
| = | - | 399 | × | 1 400 |
| x | = | - | 399 400 |
| x | = | - 0.9975 |