| ( | 4 | x | + | 2 | ) | ( | x | + | 2 | ) | = | 504 |
| Left side of the equation = | 4 | x | ( | x | + | 2 | ) | + | 2 | ( | x | + | 2 | ) |
| = | 4 | x | x | + | 4 | x | × | 2 | + | 2 | ( | x | + | 2 | ) |
| = | 4 | x | x | + | 8 | x | + | 2 | ( | x | + | 2 | ) |
| = | 4 | x | x | + | 8 | x | + | 2 | x | + | 2 | × | 2 |
| = | 4 | x | x | + | 8 | x | + | 2 | x | + | 4 |
| = | 4 | x | x | + | 10 | x | + | 4 |
| 4 | x | x | + | 10 | x | + | 4 | = | 504 |
| x1= | - | 25 2 |
| x2=10 |