| 49 | = | ( | 3 | + | x | ) | ( | 3 | + | x | ) | + | ( | 4 | + | x | ) | ( | 4 | + | x | ) |
| Right side of the equation = | 3 | ( | 3 | + | x | ) | + | x | ( | 3 | + | x | ) | + | ( | 4 | + | x | ) | ( | 4 | + | x | ) |
| = | 3 | × | 3 | + | 3 | x | + | x | ( | 3 | + | x | ) | + | ( | 4 | + | x | ) | ( | 4 | + | x | ) |
| = | 9 | + | 3 | x | + | x | ( | 3 | + | x | ) | + | ( | 4 | + | x | ) | ( | 4 | + | x | ) |
| = | 9 | + | 3 | x | + | x | × | 3 | + | x | x | + | ( | 4 | + | x | ) | ( | 4 | + | x | ) |
| = | 9 | + | 6 | x | + | x | x | + | ( | 4 | + | x | ) | ( | 4 | + | x | ) |
| = | 9 | + | 6 | x | + | x | x | + | 4 | ( | 4 | + | x | ) | + | x | ( | 4 | + | x | ) |
| = | 9 | + | 6 | x | + | x | x | + | 4 | × | 4 | + | 4 | x | + | x | ( | 4 | + | x | ) |
| = | 9 | + | 6 | x | + | x | x | + | 16 | + | 4 | x | + | x | ( | 4 | + | x | ) |
| = | 25 | + | 10 | x | + | x | x | + | x | ( | 4 | + | x | ) |
| = | 25 | + | 10 | x | + | x | x | + | x | × | 4 | + | x | x |
| = | 25 | + | 14 | x | + | x | x | + | x | x |
| 49 | = | 25 | + | 14 | x | + | x | x | + | x | x |