| A | − | ( | A | ( | 1 | − | 20 100 | ) | × | 20 100 | ) | = | 20000 |
| Left side of the equation = | A | − | A | ( | 1 | − | 20 100 | ) | × | 20 100 |
| = | A | − | A | × | 1 | × | 20 100 | + | A | × | 20 100 | × | 20 100 |
| = | A | − | A | × | 1 5 | + | A | × | 1 25 |
| = | 21 25 | A |
21 25 | A | = | 20000 |
| A | = | 20000 | ÷ | 21 25 |
| = | 20000 | × | 25 21 |
| A | = | 500000 21 |
| A | = | 23809.52381 |