| ( | 1 10 | a | + | 1 | ) | ( | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | = | 50 |
| Left side of the equation = | 1 10 | a | ( | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | + | 1 | ( | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) |
| = | 1 10 | a | a | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | + | 1 10 | a | × | 1 | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | + | 1 | ( | a | + | 1 | ) |
| = | 1 10 | a | a | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | + | 1 10 | a | ( | 20 | a | + | 1 | ) | ( | 20 | a | + | 1 | ) | + | 1 | ( | a | + | 1 | ) | ( | 20 | a | + | 1 | ) |
| = | 1 10 | a | a | × | 20 | a | ( | 20 | a | + | 1 | ) | + | 1 10 | a | a | × | 1 | ( | 20 | a | + | 1 | ) | + | 1 10 |
| = | 2 | a | a | a | ( | 20 | a | + | 1 | ) | + | 1 10 | a | a | ( | 20 | a | + | 1 | ) | + | 1 10 | a | ( | 20 | a | + | 1 | ) |
| = | 2 | a | a | a | × | 20 | a | + | 2 | a | a | a | × | 1 | + | 1 10 |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 1 10 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 1 10 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |
| = | 40 | a | a | a | a | + | 2 | a | a | a | + | 2 | a | a |