| 2 | × | 1 | + | 1 | × | 2 | + | 1 | × | 4 | + | 5 | ( | 3 | + | X | ) | = | 9 2 | ( | 7 | + | X | ) |
| Left side of the equation = | 2 | + | 2 | + | 4 | + | 5 | ( | 3 | + | X | ) |
| = | 8 | + | 5 | ( | 3 | + | X | ) |
| 8 | + | 5 | ( | 3 | + | X | ) | = | 9 2 | ( | 7 | + | X | ) |
| Left side of the equation = | 8 | + | 5 | × | 3 | + | 5 | X |
| = | 8 | + | 15 | + | 5 | X |
| = | 23 | + | 5 | X |
| 23 | + | 5 | X | = | 9 2 | ( | 7 | + | X | ) |
| Right side of the equation = | 9 2 | × | 7 | + | 9 2 | X |
| = | 63 2 | + | 9 2 | X |
| 23 | + | 5 | X | = | 63 2 | + | 9 2 | X |
| 5 | X | − | 9 2 | X | = | 63 2 | − | 23 |
1 2 | X | = | 63 2 | − | 23 |
1 2 | X | = | 17 2 |
| X | = | 17 2 | ÷ | 1 2 |
| = | 17 2 | × | 2 |
| = | 17 | × | 1 |
| X | = | 17 |