| ( | 3 | ( | 1 | + | 5 | X | ) | − | 2 | ( | 1 | + | 5 2 | X | ) | ) | ( | 1 | − | X | ) | = | 448000 |
| Left side of the equation = | 3 | ( | 1 | + | 5 | X | ) | ( | 1 | − | X | ) | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | × | 1 | ( | 1 | − | X | ) | + | 3 | × | 5 | X | ( | 1 | − | X | ) | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | ( | 1 | − | X | ) | + | 15 | X | ( | 1 | − | X | ) | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | × | 1 | − | 3 | X | + | 15 | X | ( | 1 | − | X | ) | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | − | 3 | X | + | 15 | X | ( | 1 | − | X | ) | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | − | 3 | X | + | 15 | X | × | 1 | − | 15 | X | X | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | − | 3 | X | + | 15 | X | − | 15 | X | X | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | + | 12 | X | − | 15 | X | X | − | 2 | ( | 1 | + | 5 2 | X | ) | ( | 1 | − | X | ) |
| = | 3 | + | 12 | X | − | 15 | X | X | − | 2 | × | 1 | ( | 1 | − | X | ) | − | 2 | × | 5 2 | X |
| = | 3 | + | 12 | X | − | 15 | X | X | − | 2 | ( | 1 | − | X | ) | − | 5 | X | ( | 1 | − | X | ) |
| = | 3 | + | 12 | X | − | 15 | X | X | − | 2 | × | 1 | + | 2 | X | − | 5 | X |
| = | 3 | + | 12 | X | − | 15 | X | X | − | 2 | + | 2 | X | − | 5 | X | ( | 1 | − | X | ) |
| = | 1 | + | 14 | X | − | 15 | X | X | − | 5 | X | ( | 1 | − | X | ) |
| = | 1 | + | 14 | X | − | 15 | X | X | − | 5 | X | × | 1 | + | 5 | X | X |
| = | 1 | + | 14 | X | − | 15 | X | X | − | 5 | X | + | 5 | X | X |
| = | 1 | + | 9 | X | − | 15 | X | X | + | 5 | X | X |
| 1 | + | 9 | X | − | 15 | X | X | + | 5 | X | X | = | 448000 |