| 3 | ( | ( | ( | x | − | 18 | ) | − | 6 | ) | + | 13 | ) | − | 3 | = | 5 | x | − | 58 |
| Left side of the equation = | 3 | ( | ( | x | − | 18 | ) | − | 6 | ) | + | 3 | × | 13 | − | 3 |
| = | 3 | ( | ( | x | − | 18 | ) | − | 6 | ) | + | 39 | − | 3 |
| = | 3 | ( | ( | x | − | 18 | ) | − | 6 | ) | + | 36 |
| = | 3 | ( | x | − | 18 | ) | − | 3 | × | 6 | + | 36 |
| = | 3 | ( | x | − | 18 | ) | − | 18 | + | 36 |
| = | 3 | ( | x | − | 18 | ) | + | 18 |
| = | 3 | x | − | 3 | × | 18 | + | 18 |
| = | 3 | x | − | 54 | + | 18 |
| = | 3 | x | − | 36 |
| 3 | x | − | 36 | = | 5 | x | − | 58 |
| 3 | x | − | 5 | x | = | - | 58 | + | 36 |
| - | 2 | x | = | - | 58 | + | 36 |
| - | 2 | x | = | - | 22 |
| 22 | = | 2 | x |
| 2 | x | = | 22 |
| x | = | 22 | ÷ | 2 |
| = | 22 | × | 1 2 |
| = | 11 | × | 1 |
| x | = | 11 |