12 5 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 14 5 |
| Left side of the equation = | 12 5 | × | 1 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | × | 1 | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | × | 1 | + | 12 5 | x | + | 12 5 | x | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | + | 12 5 | x | + | 12 5 | x | ( | 1 | + | x | ) | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | + | 12 5 | x | + | 12 5 | x | × | 1 | + | 12 5 | x | x | + | 12 5 | x | ( | 1 | + | x | ) |
| = | 12 5 | + | 12 5 | x | + | 12 5 | x | + | 12 5 | x | x | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | + | 24 5 | x | + | 12 5 | x | x | + | 12 5 | x | ( | 1 | + | x | ) | ( | 1 | + | x | ) |
| = | 12 5 | + | 24 5 | x | + | 12 5 | x | x | + | 12 5 | x | × | 1 | ( | 1 | + | x | ) | + | 12 5 | x |
| = | 12 5 | + | 24 5 | x | + | 12 5 | x | x | + | 12 5 | x | ( | 1 | + | x | ) | + | 12 5 | x | x |
| = | 12 5 | + | 24 5 | x | + | 12 5 | x | x | + | 12 5 | x | × | 1 | + | 12 5 | x | x |
| = | 12 5 | + | 24 5 | x | + | 12 5 | x | x | + | 12 5 | x | + | 12 5 | x | x | + | 12 5 |
| = | 12 5 | + | 36 5 | x | + | 12 5 | x | x | + | 12 5 | x | x | + | 12 5 | x | x |
| = | 12 5 | + | 36 5 | x | + | 12 5 | x | x | + | 12 5 | x | x | + | 12 5 | x | x |
| = | 12 5 | + | 36 5 | x | + | 12 5 | x | x | + | 12 5 | x | x | + | 12 5 | x | x |
12 5 | + | 36 5 | x | + | 12 5 | x | x | + | 12 5 | x | x | + | 12 5 | x | x | = | 14 5 |