| ( | 1 | + | a | ) | + | ( | 1 | − | a | ) | ( | 1 | + | 3 | a | ) | = | ( | 1 | + | 29 | ÷ | 25 | ) | a |
| Left side of the equation = | 1 | + | a | + | ( | 1 | − | a | ) | ( | 1 | + | 3 | a | ) |
| = | 1 | + | a | + | 1 | ( | 1 | + | 3 | a | ) | − | a | ( | 1 | + | 3 | a | ) |
| = | 1 | + | a | + | 1 | × | 1 | + | 1 | × | 3 | a | − | a | ( | 1 | + | 3 | a | ) |
| = | 1 | + | a | + | 1 | + | 3 | a | − | a | ( | 1 | + | 3 | a | ) |
| = | 2 | + | 4 | a | − | a | ( | 1 | + | 3 | a | ) |
| = | 2 | + | 4 | a | − | a | × | 1 | − | a | × | 3 | a |
| = | 2 | + | 3 | a | − | a | × | 3 | a |
| 2 | + | 3 | a | − | a | × | 3 | a | = | ( | 1 | + | 29 | ÷ | 25 | ) | a |
| Right side of the equation = | 1 | a | + | 29 | ÷ | 25 | × | a |
| = | 1 | a | + | 29 25 | a |
| = | 54 25 | a |
| 2 | + | 3 | a | − | a | × | 3 | a | = | 54 25 | a |