| 2 | x | + | 1 | + | 2 | ( | x | + | 1 | ) | + | x | + | 1 | = | 69 |
| Left side of the equation = | 3 | x | + | 2 | + | 2 | ( | x | + | 1 | ) |
| 3 | x | + | 2 | + | 2 | ( | x | + | 1 | ) | = | 69 |
| Left side of the equation = | 3 | x | + | 2 | + | 2 | x | + | 2 | × | 1 |
| = | 3 | x | + | 2 | + | 2 | x | + | 2 |
| = | 5 | x | + | 4 |
| 5 | x | + | 4 | = | 69 |
| 5 | x | = | 69 | − | 4 |
| 5 | x | = | 65 |
| x | = | 65 | ÷ | 5 |
| = | 65 | × | 1 5 |
| = | 13 | × | 1 |
| x | = | 13 |