| ( | 40 | − | 25 | − | y | ) | ( | 250 | + | 5 | y | ) | = | 2250 |
| Left side of the equation = | 40 | ( | 250 | + | 5 | y | ) | − | 25 | ( | 250 | + | 5 | y | ) | − | y | ( | 250 | + | 5 | y | ) |
| = | 40 | × | 250 | + | 40 | × | 5 | y | − | 25 | ( | 250 | + | 5 | y | ) | − | y | ( | 250 | + | 5 | y | ) |
| = | 10000 | + | 200 | y | − | 25 | ( | 250 | + | 5 | y | ) | − | y | ( | 250 | + | 5 | y | ) |
| = | 10000 | + | 200 | y | − | 25 | × | 250 | − | 25 | × | 5 | y | − | y | ( | 250 | + | 5 | y | ) |
| = | 10000 | + | 200 | y | − | 6250 | − | 125 | y | − | y | ( | 250 | + | 5 | y | ) |
| = | 3750 | + | 75 | y | − | y | ( | 250 | + | 5 | y | ) |
| = | 3750 | + | 75 | y | − | y | × | 250 | − | y | × | 5 | y |
| = | 3750 | − | 175 | y | − | y | × | 5 | y |
| 3750 | − | 175 | y | − | y | × | 5 | y | = | 2250 |