| ( | 440 | × | 55 | − | x | ) | × | 9 10 | + | 18 | × | 55 | = | 21010 |
| Left side of the equation = | ( | 440 | × | 55 | − | x | ) | × | 9 10 | + | 990 |
| ( | 440 | × | 55 | − | x | ) | × | 9 10 | + | 990 | = | 21010 |
| Left side of the equation = | 440 | × | 55 | × | 9 10 | − | x | × | 9 10 | + | 990 |
| = | 21780 | − | x | × | 9 10 | + | 990 |
| = | 22770 | − | 9 10 | x |
| 22770 | − | 9 10 | x | = | 21010 |
| - | 9 10 | x | = | 21010 | − | 22770 |
| - | 9 10 | x | = | - | 1760 |
| 1760 | = | 9 10 | x |
9 10 | x | = | 1760 |
| x | = | 1760 | ÷ | 9 10 |
| = | 1760 | × | 10 9 |
| x | = | 17600 9 |
| x | = | 1955.555556 |