| 2 | q | + | 10 | − | ( | q | + | 8 | ) | = | 4 | q | + | 2 | − | ( | 2 | q | + | 10 | ) |
| Left side of the equation = | 2 | q | + | 10 | − | q | − | 8 |
| = | 1 | q | + | 2 |
| 1 | q | + | 2 | = | 4 | q | + | 2 | − | ( | 2 | q | + | 10 | ) |
| Right side of the equation = | 4 | q | + | 2 | − | 2 | q | − | 10 |
| = | 2 | q | − | 8 |
| 1 | q | + | 2 | = | 2 | q | − | 8 |
| 1 | q | − | 2 | q | = | - | 8 | − | 2 |
| - | q | = | - | 8 | − | 2 |
| - | q | = | - | 8 | − | 2 |
| - | q | = | - | 10 |
| 10 | = | q |
| q | = | 10 |