| ( | s | + | 2 | ) | ( | s | − | 1 | ) | ( | s | + | 20 | ) | + | s | ( | s | + | 20 | ) | ( | s | + | 2 | ) | + | s | ( | s | − | 1 | ) | ( | s | + | 2 | ) | = | s | ( | s | + | 20 | ) | ( | s | − | 1 | ) |
| Left side of the equation = | s | ( | s | − | 1 | ) | ( | s | + | 20 | ) | + | 2 | ( | s | − | 1 | ) | ( | s | + | 20 | ) | + | s | ( | s | + | 20 | ) | ( | s | + | 2 | ) | + | s | ( | s | − | 1 | ) | ( | s | + | 2 | ) |
| = | s | s | ( | s | + | 20 | ) | − | s | × | 1 | ( | s | + | 20 | ) | + | 2 | ( | s | − | 1 | ) | ( | s | + | 20 | ) | + | s | ( | s | + | 20 | ) | ( | s | + | 2 | ) |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | ( | s | + | 20 | ) | + | 2 | ( | s | − | 1 | ) | ( | s | + | 20 | ) |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | − | s | × | 1 | × | 20 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | − | s | × | 20 | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | − | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | − | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | − | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | − | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 20 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 18 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 18 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 18 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 18 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 18 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 58 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 58 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 58 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 58 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 58 | s | + | 2 |
| = | s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 56 | s | + | 2 |
| s | s | s | + | s | s | × | 20 | − | s | × | 1 | s | + | 56 | s | + | 2 | = | s | ( | s | + | 20 | ) | ( | s | − | 1 | ) |
| Right side of the equation = | s | s | ( | s | − | 1 | ) | + | s | × | 20 | ( | s | − | 1 | ) |