| ( | 5 | y | + | 1 | ) | + | ( | 1 | − | y | ) | = | ( | 9 | y | + | 1 | ) | + | ( | 1 | − | 3 | y | ) |
| Left side of the equation = | 5 | y | + | 1 | + | ( | 1 | − | y | ) |
| = | 5 | y | + | 1 | + | 1 | − | y |
| = | 4 | y | + | 2 |
| 4 | y | + | 2 | = | ( | 9 | y | + | 1 | ) | + | ( | 1 | − | 3 | y | ) |
| Right side of the equation = | 9 | y | + | 1 | + | ( | 1 | − | 3 | y | ) |
| = | 9 | y | + | 1 | + | 1 | − | 3 | y |
| = | 6 | y | + | 2 |
| 4 | y | + | 2 | = | 6 | y | + | 2 |
| 4 | y | − | 6 | y | = | 2 | − | 2 |
| - | 2 | y | = | 2 | − | 2 |
| - | 2 | y | = | 0 |
| - | 0 | = | 2 | y |
| 2 | y | = | - | 0 |
| y | = | - | 0 | ÷ | 2 |
| = | - | 0 | × | 1 2 |
| y | = | 0 |