| ( | ( | 27 2 | − | X | ) | × | 200 | + | 500 | ) | ( | X | − | 5 2 | ) | = | 9100 |
| Left side of the equation = | ( | 27 2 | − | X | ) | × | 200 | ( | X | − | 5 2 | ) | + | 500 | ( | X | − | 5 2 | ) |
| = | 27 2 | × | 200 | ( | X | − | 5 2 | ) | − | X | × | 200 | ( | X | − | 5 2 | ) | + | 500 | ( | X | − | 5 2 | ) |
| = | 2700 | ( | X | − | 5 2 | ) | − | X | × | 200 | ( | X | − | 5 2 | ) | + | 500 | ( | X | − | 5 2 | ) |
| = | 2700 | X | − | 2700 | × | 5 2 | − | X | × | 200 | ( | X | − | 5 2 | ) | + | 500 | ( | X | − | 5 2 | ) |
| = | 2700 | X | − | 6750 | − | X | × | 200 | ( | X | − | 5 2 | ) | + | 500 | ( | X | − | 5 2 | ) |
| = | 2700 | X | − | 6750 | − | X | × | 200 | X | + | X | × | 200 | × | 5 2 | + | 500 | ( | X | − | 5 2 | ) |
| = | 2700 | X | − | 6750 | − | X | × | 200 | X | + | X | × | 500 | + | 500 | ( | X | − | 5 2 | ) |
| = | 3200 | X | − | 6750 | − | X | × | 200 | X | + | 500 | ( | X | − | 5 2 | ) |
| = | 3200 | X | − | 6750 | − | X | × | 200 | X | + | 500 | X | − | 500 | × | 5 2 |
| = | 3200 | X | − | 6750 | − | X | × | 200 | X | + | 500 | X | − | 1250 |
| = | 3700 | X | − | 8000 | − | X | × | 200 | X |
| 3700 | X | − | 8000 | − | X | × | 200 | X | = | 9100 |
| X2= | 19 2 |