| 7 | X | + | 13 | = | 5 | X | − | 10 |
| 7 | X | − | 5 | X | = | - | 10 | − | 13 |
| 2 | X | = | - | 10 | − | 13 |
| 2 | X | = | - | 23 |
| X | = | - | 23 | ÷ | 2 |
| = | - | 23 | × | 1 2 |
| X | = | - | 23 2 |
| X | = | - 11.5 |
| 8 | X | + | 4 | = | 5 | + | 3 | X |
| 8 | X | − | 3 | X | = | 5 | − | 4 |
| 5 | X | = | 5 | − | 4 |
| 5 | X | = | 1 |
| X | = | 1 | ÷ | 5 |
| = | 1 | × | 1 5 |
| X | = | 1 5 |
| X | = | 0.2 |
| 5 | X | − | 10 | = | 4 | X | + | 10 |
| 5 | X | − | 4 | X | = | 10 | + | 10 |
| X | = | 10 | + | 10 |
| X | = | 10 | + | 10 |
| X | = | 20 |
| 30 | − | 2 | X | = | 4 | X | − | 8 |
| - | 2 | X | − | 4 | X | = | - | 8 | − | 30 |
| - | 6 | X | = | - | 8 | − | 30 |
| - | 6 | X | = | - | 38 |
| 38 | = | 6 | X |
| 6 | X | = | 38 |
| X | = | 38 | ÷ | 6 |
| = | 38 | × | 1 6 |
| = | 19 | × | 1 3 |
| X | = | 19 3 |
| X | = | 6.333333 |