| ( | 80 | − | y | − | 65 | ) | ( | 100 | + | 10 | y | ) | = | 1560 |
| Left side of the equation = | 80 | ( | 100 | + | 10 | y | ) | − | y | ( | 100 | + | 10 | y | ) | − | 65 | ( | 100 | + | 10 | y | ) |
| = | 80 | × | 100 | + | 80 | × | 10 | y | − | y | ( | 100 | + | 10 | y | ) | − | 65 | ( | 100 | + | 10 | y | ) |
| = | 8000 | + | 800 | y | − | y | ( | 100 | + | 10 | y | ) | − | 65 | ( | 100 | + | 10 | y | ) |
| = | 8000 | + | 800 | y | − | y | × | 100 | − | y | × | 10 | y | − | 65 | ( | 100 | + | 10 | y | ) |
| = | 8000 | + | 700 | y | − | y | × | 10 | y | − | 65 | ( | 100 | + | 10 | y | ) |
| = | 8000 | + | 700 | y | − | y | × | 10 | y | − | 65 | × | 100 | − | 65 | × | 10 | y |
| = | 8000 | + | 700 | y | − | y | × | 10 | y | − | 6500 | − | 650 | y |
| = | 1500 | + | 50 | y | − | y | × | 10 | y |
| 1500 | + | 50 | y | − | y | × | 10 | y | = | 1560 |