23 10 | ( | 1 | + | X | ) | ( | 1 | + | X | ) | = | 13 4 |
| Left side of the equation = | 23 10 | × | 1 | ( | 1 | + | X | ) | + | 23 10 | X | ( | 1 | + | X | ) |
| = | 23 10 | ( | 1 | + | X | ) | + | 23 10 | X | ( | 1 | + | X | ) |
| = | 23 10 | × | 1 | + | 23 10 | X | + | 23 10 | X | ( | 1 | + | X | ) |
| = | 23 10 | + | 23 10 | X | + | 23 10 | X | ( | 1 | + | X | ) |
| = | 23 10 | + | 23 10 | X | + | 23 10 | X | × | 1 | + | 23 10 | X | X |
| = | 23 10 | + | 23 10 | X | + | 23 10 | X | + | 23 10 | X | X |
| = | 23 10 | + | 23 5 | X | + | 23 10 | X | X |
23 10 | + | 23 5 | X | + | 23 10 | X | X | = | 13 4 |