| 2 | ÷ | 21 | × | x | − | 2 | ÷ | 21 | = | 1 | ÷ | 7 | × | x | − | 13 | ÷ | 35 |
| Left side of the equation = | 2 21 | x | − | 2 21 |
2 21 | x | − | 2 21 | = | 1 | ÷ | 7 | × | x | − | 13 | ÷ | 35 |
| Right side of the equation = | 1 7 | x | − | 13 35 |
2 21 | x | − | 2 21 | = | 1 7 | x | − | 13 35 |
2 21 | x | − | 1 7 | x | = | - | 13 35 | + | 2 21 |
| - | 1 21 | x | = | - | 13 35 | + | 2 21 |
| - | 1 21 | x | = | - | 29 105 |
29 105 | = | 1 21 | x |
1 21 | x | = | 29 105 |
| x | = | 29 105 | ÷ | 1 21 |
| = | 29 105 | × | 21 |
| = | 29 5 | × | 1 |
| x | = | 29 5 |
| x | = | 5.8 |