| ( | 2 | ( | - | 1 | ) | − | y | ) | ÷ | 2 | − | ( | - | 1 | − | 3 | ) | ÷ | 2 | = | 1 |
| Left side of the equation = | 2 | ( | - | 1 | ) | × | 1 2 | − | y | × | 1 2 | − | ( | - | 1 | − | 3 | ) | × | 1 2 |
| = | 1 | ( | - | 1 | ) | − | y | × | 1 2 | − | ( | - | 1 | − | 3 | ) | × | 1 2 |
| = | - | 1 | × | 1 | − | 1 2 | y | − | ( | - | 1 | − | 3 | ) | × | 1 2 |
| = | - | 1 | − | 1 2 | y | − | ( | - | 1 | − | 3 | ) | × | 1 2 |
| = | - | 1 | − | 1 2 | y | + | 1 | × | 1 2 | + | 3 | × | 1 2 |
| = | - | 1 | − | 1 2 | y | + | 1 2 | + | 3 2 |
| = | 1 | − | 1 2 | y |
| 1 | − | 1 2 | y | = | 1 |
| - | 1 2 | y | = | 1 | − | 1 |
| - | 1 2 | y | = | 0 |
| - | 0 | = | 1 2 | y |
1 2 | y | = | - | 0 |
| y | = | - | 0 | ÷ | 1 2 |
| = | - | 0 | × | 2 |
| y | = | 0 |