| ( | a | + | 1 | ) | ( | a | ÷ | 5 | + | 1 | ) | ( | a | ÷ | 25 | + | 1 | ) | + | 15 | = | 0 |
| Left side of the equation = | a | ( | a | ÷ | 5 | + | 1 | ) | ( | a | ÷ | 25 | + | 1 | ) | + | 1 | ( | a | ÷ | 5 | + | 1 | ) | ( | a | ÷ | 25 | + | 1 | ) | + | 15 |
| = | a | a | ÷ | 5 | × | ( | a | ÷ | 25 | + | 1 | ) | + | a | × | 1 | ( | a | ÷ | 25 | + | 1 | ) | + | 1 | ( | a | ÷ | 5 | + | 1 | ) | ( | a | ÷ | 25 | + | 1 | ) | + | 15 |
| = | a | a | × | 1 5 | a | ÷ | 25 | + | a | a | × | 1 5 | × | 1 | + | a | × | 1 | ( | a | ÷ | 25 | + | 1 | ) |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 | ( | a | ÷ | 25 | + | 1 | ) | + | 1 | ( | a | ÷ | 5 | + | 1 | ) |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 | a | ÷ | 25 | + | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | a | × | 1 |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 1 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 1 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 1 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 1 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 6 5 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 6 5 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 6 5 | a |
| = | a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 31 25 | a |
| a | a | × | 1 125 | a | + | a | a | × | 1 5 | + | a | × | 1 25 | a | + | 31 25 | a | = | 0 |