| x | + | ( | x | + | 1 | ) | + | ( | x | + | 6 | ) | + | ( | x | + | 7 | ) | = | 4 | x | + | 14 |
| Left side of the equation = | x | + | x | + | 1 | + | ( | x | + | 6 | ) | + | ( | x | + | 7 | ) |
| = | 2 | x | + | 1 | + | ( | x | + | 6 | ) | + | ( | x | + | 7 | ) |
| = | 2 | x | + | 1 | + | x | + | 6 | + | ( | x | + | 7 | ) |
| = | 3 | x | + | 7 | + | ( | x | + | 7 | ) |
| = | 3 | x | + | 7 | + | x | + | 7 |
| = | 4 | x | + | 14 |
| 4 | x | + | 14 | = | 4 | x | + | 14 |
| 4 | x | − | 4 | x | = | 14 | − | 14 |
| 0 | x | = | 14 | − | 14 |
| 0 | x | = | 0 |