| 2 | ( | q | + | 3 | ( | 5 | − | 2 | q | ) | ) | = | - | 10 |
| Left side of the equation = | 2 | q | + | 2 | × | 3 | ( | 5 | − | 2 | q | ) |
| = | 2 | q | + | 6 | ( | 5 | − | 2 | q | ) |
| = | 2 | q | + | 6 | × | 5 | − | 6 | × | 2 | q |
| = | 2 | q | + | 30 | − | 12 | q |
| = | - | 10 | q | + | 30 |
| - | 10 | q | + | 30 | = | - | 10 |
| - | 10 | q | = | - | 10 | − | 30 |
| - | 10 | q | = | - | 40 |
| 40 | = | 10 | q |
| 10 | q | = | 40 |
| q | = | 40 | ÷ | 10 |
| = | 40 | × | 1 10 |
| = | 4 | × | 1 |
| q | = | 4 |