| ( | 12 | x | − | 11 | ) | ( | 2200 | + | 2200 | x | ) | = | 0 |
| Left side of the equation = | 12 | x | ( | 2200 | + | 2200 | x | ) | − | 11 | ( | 2200 | + | 2200 | x | ) |
| = | 12 | x | × | 2200 | + | 12 | x | × | 2200 | x | − | 11 | ( | 2200 | + | 2200 | x | ) |
| = | 26400 | x | + | 26400 | x | x | − | 11 | ( | 2200 | + | 2200 | x | ) |
| = | 26400 | x | + | 26400 | x | x | − | 11 | × | 2200 | − | 11 | × | 2200 | x |
| = | 26400 | x | + | 26400 | x | x | − | 24200 | − | 24200 | x |
| = | 2200 | x | + | 26400 | x | x | − | 24200 |
| 2200 | x | + | 26400 | x | x | − | 24200 | = | 0 |
| x2= | 11 12 |