| ( | 100 | y | − | 5 | y | ) | − | ( | 400 | + | 200 | ) | = | 0 |
| Left side of the equation = | 100 | y | − | 5 | y | − | ( | 400 | + | 200 | ) |
| = | 95 | y | − | ( | 400 | + | 200 | ) |
| = | 95 | y | − | 400 | − | 200 |
| = | 95 | y | − | 600 |
| 95 | y | − | 600 | = | 0 |
| 95 | y | = | 0 | + | 600 |
| 95 | y | = | 600 |
| y | = | 600 | ÷ | 95 |
| = | 600 | × | 1 95 |
| = | 120 | × | 1 19 |
| y | = | 120 19 |
| y | = | 6.315789 |