1 10 | X | + | ( | 21 | − | X | ) | × | 3 4 | = | 21 | × | 1 2 |
| Left side of the equation = | 1 10 | X | + | 21 | × | 3 4 | − | X | × | 3 4 |
| = | 1 10 | X | + | 63 4 | − | X | × | 3 4 |
| = | - | 13 20 | X | + | 63 4 |
| - | 13 20 | X | + | 63 4 | = | 21 | × | 1 2 |
| Right side of the equation = | 21 2 |
| - | 13 20 | X | + | 63 4 | = | 21 2 |
| - | 13 20 | X | = | 21 2 | − | 63 4 |
| - | 13 20 | X | = | - | 21 4 |
21 4 | = | 13 20 | X |
13 20 | X | = | 21 4 |
| X | = | 21 4 | ÷ | 13 20 |
| = | 21 4 | × | 20 13 |
| = | 21 | × | 5 13 |
| X | = | 105 13 |
| X | = | 8.076923 |