| 2 | a | ÷ | 7 | − | ( | 1 | − | 2 | a | − | 7 | ) | ÷ | 3 | = | ( | 2 | a | ÷ | 7 | + | a | ) | ÷ | 6 |
| Left side of the equation = | 2 7 | a | − | ( | 1 | − | 2 | a | − | 7 | ) | × | 1 3 |
2 7 | a | − | ( | 1 | − | 2 | a | − | 7 | ) | × | 1 3 | = | ( | 2 | a | ÷ | 7 | + | a | ) | ÷ | 6 |
| Left side of the equation = | 2 7 | a | − | 1 | × | 1 3 | + | 2 | a | × | 1 3 | + | 7 | × | 1 3 |
| = | 2 7 | a | − | 1 3 | + | 2 3 | a | + | 7 3 |
| = | 20 21 | a | + | 2 |
20 21 | a | + | 2 | = | ( | 2 | a | ÷ | 7 | + | a | ) | ÷ | 6 |
| Right side of the equation = | 2 | a | ÷ | 7 | × | 1 6 | + | a | × | 1 6 |
| = | 1 21 | a | + | a | × | 1 6 |
| = | 3 14 | a |
20 21 | a | + | 2 | = | 3 14 | a |
20 21 | a | − | 3 14 | a | = | - | 2 |
31 42 | a | = | - | 2 |
| a | = | - | 2 | ÷ | 31 42 |
| = | - | 2 | × | 42 31 |
| a | = | - | 84 31 |
| a | = | - 2.709677 |