| 1 | − | ( | x | − | ( | 26 | − | 10 | x | ) | ÷ | 3 | ) | ÷ | 13 | = | x | ÷ | 2 | − | ( | 7 | x | − | ( | 21 | − | 7 | x | ) | ÷ | 2 | ) | ÷ | 21 |
| Left side of the equation = | 1 | − | x | × | 1 13 | + | ( | 26 | − | 10 | x | ) | ÷ | 3 | × | 1 13 |
| = | 1 | − | x | × | 1 13 | + | ( | 26 | − | 10 | x | ) | × | 1 39 |
| = | 1 | − | 1 13 | x | + | 26 | × | 1 39 | − | 10 | x | × | 1 39 |
| = | 1 | − | 1 13 | x | + | 2 3 | − | 10 39 | x |
| = | 5 3 | − | 1 3 | x |
5 3 | − | 1 3 | x | = | x | ÷ | 2 | − | ( | 7 | x | − | ( | 21 | − | 7 | x | ) | ÷ | 2 | ) | ÷ | 21 |
| Right side of the equation = | 1 2 | x | − | 7 | x | × | 1 21 | + | ( | 21 | − | 7 | x | ) | ÷ | 2 | × | 1 21 |
| = | 1 2 | x | − | 1 3 | x | + | ( | 21 | − | 7 | x | ) | × | 1 42 |
| = | 1 6 | x | + | ( | 21 | − | 7 | x | ) | × | 1 42 |
| = | 1 6 | x | + | 21 | × | 1 42 | − | 7 | x | × | 1 42 |
| = | 1 6 | x | + | 1 2 | − | 1 6 | x |
| = | 0 | x | + | 1 2 |
5 3 | − | 1 3 | x | = | 1 2 |
| - | 1 3 | x | = | 1 2 | − | 5 3 |
| - | 1 3 | x | = | - | 7 6 |
7 6 | = | 1 3 | x |
1 3 | x | = | 7 6 |
| x | = | 7 6 | ÷ | 1 3 |
| = | 7 6 | × | 3 |
| = | 7 2 | × | 1 |
| x | = | 7 2 |
| x | = | 3.5 |