| ( | 51 | + | x | ) | ( | x | − | 51 | ) | ÷ | 2 | = | 1275 |
| Left side of the equation = | 51 | ( | x | − | 51 | ) | × | 1 2 | + | x | ( | x | − | 51 | ) | × | 1 2 |
| = | 51 2 | ( | x | − | 51 | ) | + | x | ( | x | − | 51 | ) | × | 1 2 |
| = | 51 2 | x | − | 51 2 | × | 51 | + | x | ( | x | − | 51 | ) | × | 1 2 |
| = | 51 2 | x | − | 2601 2 | + | x | ( | x | − | 51 | ) | × | 1 2 |
| = | 51 2 | x | − | 2601 2 | + | x | x | × | 1 2 | − | x | × | 51 | × | 1 2 |
| = | 51 2 | x | − | 2601 2 | + | x | x | × | 1 2 | − | x | × | 51 2 |
| = | 0 | x | − | 2601 2 | + | x | x | × | 1 2 |
| 0 | x | − | 2601 2 | + | x | x | × | 1 2 | = | 1275 |