| ( | a | + | 4 | ) | ( | a | + | 4 | ) | + | 1 | = | 25 | ÷ | 16 | + | ( | a | + | 25 | ÷ | 4 | ) | ( | a | + | 25 | ÷ | 4 | ) |
| Left side of the equation = | a | ( | a | + | 4 | ) | + | 4 | ( | a | + | 4 | ) | + | 1 |
| = | a | a | + | a | × | 4 | + | 4 | ( | a | + | 4 | ) | + | 1 |
| = | a | a | + | 4 | a | + | 4 | a | + | 4 | × | 4 | + | 1 |
| = | a | a | + | 4 | a | + | 4 | a | + | 16 | + | 1 |
| = | a | a | + | 8 | a | + | 17 |
| a | a | + | 8 | a | + | 17 | = | 25 | ÷ | 16 | + | ( | a | + | 25 | ÷ | 4 | ) | ( | a | + | 25 | ÷ | 4 | ) |
| Right side of the equation = | 25 16 | + | ( | a | + | 25 | ÷ | 4 | ) | ( | a | + | 25 | ÷ | 4 | ) |
| a | a | + | 8 | a | + | 17 | = | 25 16 | + | ( | a | + | 25 | ÷ | 4 | ) | ( | a | + | 25 | ÷ | 4 | ) |
| Right side of the equation = | 25 16 | + | a | ( | a | + | 25 | ÷ | 4 | ) | + | 25 | ÷ | 4 | × | ( | a | + | 25 | ÷ | 4 | ) |
| = | 25 16 | + | a | ( | a | + | 25 | ÷ | 4 | ) | + | 25 4 | ( | a | + | 25 | ÷ | 4 | ) |
| = | 25 16 | + | a | a | + | a | × | 25 | ÷ | 4 | + | 25 4 | ( | a | + | 25 | ÷ | 4 | ) |
| = | 25 16 | + | a | a | + | a | × | 25 4 | + | 25 4 | ( | a | + | 25 | ÷ | 4 | ) |
| = | 25 16 | + | a | a | + | 25 4 | a | + | 25 4 | a | + | 25 4 | × | 25 | ÷ | 4 |
| = | 25 16 | + | a | a | + | 25 4 | a | + | 25 4 | a | + | 625 16 |
| = | 325 8 | + | a | a | + | 25 2 | a |
| a | a | + | 8 | a | + | 17 | = | 325 8 | + | a | a | + | 25 2 | a |
| a= | - | 21 4 |