| ( | ( | 10 | − | X | ) | × | 10 | + | X | ) | ( | 10 | X | + | 10 | − | X | ) | = | 2701 |
| Left side of the equation = | ( | 10 | − | X | ) | × | 10 | ( | 10 | X | + | 10 | − | X | ) | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 10 | × | 10 | ( | 10 | X | + | 10 | − | X | ) | − | X | × | 10 | ( | 10 | X | + | 10 | − | X | ) | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 100 | ( | 10 | X | + | 10 | − | X | ) | − | X | × | 10 | ( | 10 | X | + | 10 | − | X | ) | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 100 | × | 10 | X | + | 100 | × | 10 | − | 100 | X | − | X | × | 10 | ( | 10 | X | + | 10 | − | X | ) | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 1000 | X | + | 1000 | − | 100 | X | − | X | × | 10 | ( | 10 | X | + | 10 | − | X | ) | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 900 | X | + | 1000 | − | X | × | 10 | ( | 10 | X | + | 10 | − | X | ) | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 900 | X | + | 1000 | − | X | × | 10 | × | 10 | X | − | X | × | 10 | × | 10 | + | X | × | 10 |
| = | 900 | X | + | 1000 | − | X | × | 100 | X | − | X | × | 100 | + | X | × | 10 | X | + | X |
| = | 800 | X | + | 1000 | − | X | × | 100 | X | + | X | × | 10 | X | + | X | ( | 10 | X | + | 10 | − | X | ) |
| = | 800 | X | + | 1000 | − | X | × | 100 | X | + | X | × | 10 | X | + | X | × | 10 | X |
| = | 810 | X | + | 1000 | − | X | × | 100 | X | + | X | × | 10 | X | + | X | × | 10 | X |
| 810 | X | + | 1000 | − | X | × | 100 | X | + | X | × | 10 | X | + | X | × | 10 | X | = | 2701 |