| ( | 30 | ( | 25 | − | 6 | − | x | ) | + | 300 | ) | ( | 25 | − | x | − | 6 | ) | = | 6300 |
| Left side of the equation = | 30 | ( | 25 | − | 6 | − | x | ) | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 30 | × | 25 | ( | 25 | − | x | − | 6 | ) | − | 30 | × | 6 | ( | 25 | − | x | − | 6 | ) | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 750 | ( | 25 | − | x | − | 6 | ) | − | 180 | ( | 25 | − | x | − | 6 | ) | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 750 | × | 25 | − | 750 | x | − | 750 | × | 6 | − | 180 | ( | 25 | − | x | − | 6 | ) | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 |
| = | 18750 | − | 750 | x | − | 4500 | − | 180 | ( | 25 | − | x | − | 6 | ) | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 14250 | − | 750 | x | − | 180 | ( | 25 | − | x | − | 6 | ) | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 14250 | − | 750 | x | − | 180 | × | 25 | + | 180 | x | + | 180 | × | 6 | − | 30 | x | ( | 25 | − | x | − | 6 | ) |
| = | 14250 | − | 750 | x | − | 4500 | + | 180 | x | + | 1080 | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 10830 | − | 570 | x | − | 30 | x | ( | 25 | − | x | − | 6 | ) | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 10830 | − | 570 | x | − | 30 | x | × | 25 | + | 30 | x | x | + | 30 | x | × | 6 |
| = | 10830 | − | 570 | x | − | 750 | x | + | 30 | x | x | + | 180 | x | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 10830 | − | 1140 | x | + | 30 | x | x | + | 300 | ( | 25 | − | x | − | 6 | ) |
| = | 10830 | − | 1140 | x | + | 30 | x | x | + | 300 | × | 25 | − | 300 | x | − | 300 | × | 6 |
| = | 10830 | − | 1140 | x | + | 30 | x | x | + | 7500 | − | 300 | x | − | 1800 |
| = | 16530 | − | 1440 | x | + | 30 | x | x |
| 16530 | − | 1440 | x | + | 30 | x | x | = | 6300 |