| 20 | × | 30 | − | ( | 20 | x | + | 30 | x | − | x | × | 2 | ) | = | 551 |
| Left side of the equation = | 600 | − | ( | 20 | x | + | 30 | x | − | x | × | 2 | ) |
| 600 | − | ( | 20 | x | + | 30 | x | − | x | × | 2 | ) | = | 551 |
| Left side of the equation = | 600 | − | 20 | x | − | 30 | x | + | x | × | 2 |
| = | 600 | − | 48 | x |
| 600 | − | 48 | x | = | 551 |
| - | 48 | x | = | 551 | − | 600 |
| - | 48 | x | = | - | 49 |
| 49 | = | 48 | x |
| 48 | x | = | 49 |
| x | = | 49 | ÷ | 48 |
| = | 49 | × | 1 48 |
| x | = | 49 48 |
| x | = | 1.020833 |