| 21 | + | 21 | × | 3 20 | ( | x | − | 1 | ) | = | 6 | x |
| Left side of the equation = | 21 | + | 63 20 | ( | x | − | 1 | ) |
| 21 | + | 63 20 | ( | x | − | 1 | ) | = | 6 | x |
| Left side of the equation = | 21 | + | 63 20 | x | − | 63 20 | × | 1 |
| = | 21 | + | 63 20 | x | − | 63 20 |
| = | 357 20 | + | 63 20 | x |
357 20 | + | 63 20 | x | = | 6 | x |
63 20 | x | − | 6 | x | = | - | 357 20 |
| - | 57 20 | x | = | - | 357 20 |
357 20 | = | 57 20 | x |
57 20 | x | = | 357 20 |
| x | = | 357 20 | ÷ | 57 20 |
| = | 357 20 | × | 20 57 |
| = | 119 | × | 1 19 |
| x | = | 119 19 |
| x | = | 6.263158 |