| 30 | x | × | 4 5 | = | 30 | x | − | 150 | × | 9 10 |
| Left side of the equation = | 24 | x |
| 24 | x | = | 30 | x | − | 150 | × | 9 10 |
| Right side of the equation = | 30 | x | − | 135 |
| 24 | x | = | 30 | x | − | 135 |
| 24 | x | − | 30 | x | = | - | 135 |
| - | 6 | x | = | - | 135 |
| 135 | = | 6 | x |
| 6 | x | = | 135 |
| x | = | 135 | ÷ | 6 |
| = | 135 | × | 1 6 |
| = | 45 | × | 1 2 |
| x | = | 45 2 |
| x | = | 22.5 |