| 2 | x | × | 10 | − | 8 | = | 4 | ( | 40 | − | x | ) |
| Left side of the equation = | 20 | x | − | 8 |
| 20 | x | − | 8 | = | 4 | ( | 40 | − | x | ) |
| Right side of the equation = | 4 | × | 40 | − | 4 | x |
| = | 160 | − | 4 | x |
| 20 | x | − | 8 | = | 160 | − | 4 | x |
| 20 | x | + | 4 | x | = | 160 | + | 8 |
| 24 | x | = | 160 | + | 8 |
| 24 | x | = | 168 |
| x | = | 168 | ÷ | 24 |
| = | 168 | × | 1 24 |
| = | 7 | × | 1 |
| x | = | 7 |