| ( | 40 | − | 2 | X | ) | ( | 26 | − | 2 | X | ) | = | 0 |
| Left side of the equation = | 40 | ( | 26 | − | 2 | X | ) | − | 2 | X | ( | 26 | − | 2 | X | ) |
| = | 40 | × | 26 | − | 40 | × | 2 | X | − | 2 | X | ( | 26 | − | 2 | X | ) |
| = | 1040 | − | 80 | X | − | 2 | X | ( | 26 | − | 2 | X | ) |
| = | 1040 | − | 80 | X | − | 2 | X | × | 26 | + | 2 | X | × | 2 | X |
| = | 1040 | − | 80 | X | − | 52 | X | + | 4 | X | X |
| = | 1040 | − | 132 | X | + | 4 | X | X |
| 1040 | − | 132 | X | + | 4 | X | X | = | 0 |