| 58 | ( | 1 | + | r | − | 2 | × | 19 20 | r | ) | = | 1 | + | r |
| Left side of the equation = | 58 | × | 1 | + | 58 | r | − | 58 | × | 2 | × | 19 20 | r |
| = | 58 | + | 58 | r | − | 551 5 | r |
| = | 58 | − | 261 5 | r |
| 58 | − | 261 5 | r | = | 1 | + | r |
| - | 261 5 | r | − | r | = | 1 | − | 58 |
| - | 266 5 | r | = | 1 | − | 58 |
| - | 266 5 | r | = | - | 57 |
| 57 | = | 266 5 | r |
266 5 | r | = | 57 |
| r | = | 57 | ÷ | 266 5 |
| = | 57 | × | 5 266 |
| = | 3 | × | 5 14 |
| r | = | 15 14 |
| r | = | 1.071429 |