| 4002 | − | 38 | x | = | 30 | ( | 4 | x | + | 7 | ) |
| Right side of the equation = | 30 | × | 4 | x | + | 30 | × | 7 |
| = | 120 | x | + | 210 |
| 4002 | − | 38 | x | = | 120 | x | + | 210 |
| - | 38 | x | − | 120 | x | = | 210 | − | 4002 |
| - | 158 | x | = | 210 | − | 4002 |
| - | 158 | x | = | - | 3792 |
| 3792 | = | 158 | x |
| 158 | x | = | 3792 |
| x | = | 3792 | ÷ | 158 |
| = | 3792 | × | 1 158 |
| = | 24 | × | 1 |
| x | = | 24 |