| 30 | + | X | = | 93 100 | ( | 30 | + | X | ) |
| Right side of the equation = | 93 100 | × | 30 | + | 93 100 | X |
| = | 279 10 | + | 93 100 | X |
| 30 | + | X | = | 279 10 | + | 93 100 | X |
| X | − | 93 100 | X | = | 279 10 | − | 30 |
7 100 | X | = | 279 10 | − | 30 |
7 100 | X | = | - | 21 10 |
| X | = | - | 21 10 | ÷ | 7 100 |
| = | - | 21 10 | × | 100 7 |
| = | - | 3 | × | 10 |
| X | = | - | 30 |