| ( | x | − | 250 | ) | ( | 290 | − | x | ÷ | 5 | × | x | × | 4 | + | 16 | ) | = | 720 |
| Left side of the equation = | x | ( | 290 | − | x | ÷ | 5 | × | x | × | 4 | + | 16 | ) | − | 250 | ( | 290 | − | x | ÷ | 5 | × | x | × | 4 | + | 16 | ) |
| = | x | × | 290 | − | x | x | ÷ | 5 | × | x | × | 4 | + | x | × | 16 | − | 250 | ( | 290 | − | x | ÷ | 5 | × | x | × | 4 | + | 16 | ) |
| = | x | × | 290 | − | x | x | × | 4 5 | x | + | x | × | 16 | − | 250 | ( | 290 | − | x | ÷ | 5 | × | x | × | 4 | + | 16 | ) |
| = | 306 | x | − | x | x | × | 4 5 | x | − | 250 | ( | 290 | − | x | ÷ | 5 | × | x | × | 4 | + | 16 | ) |
| = | 306 | x | − | x | x | × | 4 5 | x | − | 250 | × | 290 | + | 250 | x | ÷ | 5 | × | x |
| = | 306 | x | − | x | x | × | 4 5 | x | − | 72500 | + | 200 | x | x | − | 4000 |
| = | 306 | x | − | x | x | × | 4 5 | x | − | 76500 | + | 200 | x | x |
| 306 | x | − | x | x | × | 4 5 | x | − | 76500 | + | 200 | x | x | = | 720 |