| 15 | A | + | 21 10 | ( | 100 | − | A | ) | = | 34 5 |
| Left side of the equation = | 15 | A | + | 21 10 | × | 100 | − | 21 10 | A |
| = | 15 | A | + | 210 | − | 21 10 | A |
| = | 129 10 | A | + | 210 |
129 10 | A | + | 210 | = | 34 5 |
129 10 | A | = | 34 5 | − | 210 |
129 10 | A | = | - | 1016 5 |
| A | = | - | 1016 5 | ÷ | 129 10 |
| = | - | 1016 5 | × | 10 129 |
| = | - | 1016 | × | 2 129 |
| A | = | - | 2032 129 |
| A | = | - 15.751938 |