| ( | 24 | − | x | ) | × | 6 | = | ( | 21 | − | x | ) | × | 8 |
| Left side of the equation = | 24 | × | 6 | − | x | × | 6 |
| = | 144 | − | x | × | 6 |
| 144 | − | 6 | x | = | ( | 21 | − | x | ) | × | 8 |
| Right side of the equation = | 21 | × | 8 | − | x | × | 8 |
| = | 168 | − | x | × | 8 |
| 144 | − | 6 | x | = | 168 | − | 8 | x |
| - | 6 | x | + | 8 | x | = | 168 | − | 144 |
| 2 | x | = | 168 | − | 144 |
| 2 | x | = | 24 |
| x | = | 24 | ÷ | 2 |
| = | 24 | × | 1 2 |
| = | 12 | × | 1 |
| x | = | 12 |