| 3 | x | × | 3 | x | − | 16 | ( | 25 | ÷ | 12 | − | x | ) | ( | 25 | ÷ | 12 | − | x | ) | = | 7 |
| Left side of the equation = | 9 | x | x | − | 16 | ( | 25 | ÷ | 12 | − | x | ) | ( | 25 | ÷ | 12 | − | x | ) |
| 9 | x | x | − | 16 | ( | 25 | ÷ | 12 | − | x | ) | ( | 25 | ÷ | 12 | − | x | ) | = | 7 |
| Left side of the equation = | 9 | x | x | − | 16 | × | 25 | ÷ | 12 | × | ( | 25 | ÷ | 12 | − | x | ) | + | 16 | x | ( | 25 | ÷ | 12 | − | x | ) |
| = | 9 | x | x | − | 100 3 | ( | 25 | ÷ | 12 | − | x | ) | + | 16 | x | ( | 25 | ÷ | 12 | − | x | ) |
| = | 9 | x | x | − | 100 3 | × | 25 | ÷ | 12 | + | 100 3 | x | + | 16 | x | ( | 25 | ÷ | 12 | − | x | ) |
| = | 9 | x | x | − | 625 9 | + | 100 3 | x | + | 16 | x | ( | 25 | ÷ | 12 | − | x | ) |
| = | 9 | x | x | − | 625 9 | + | 100 3 | x | + | 16 | x | × | 25 | ÷ | 12 | − | 16 | x |
| = | 9 | x | x | − | 625 9 | + | 100 3 | x | + | 100 3 | x | − | 16 | x | x |
| = | 9 | x | x | − | 625 9 | + | 200 3 | x | − | 16 | x | x |
| 9 | x | x | − | 625 9 | + | 200 3 | x | − | 16 | x | x | = | 7 |
| x1= | 4 3 |