| 60 | × | 45 | ( | 1 | − | 1 100 | x | ) | + | 20 | ( | 1 | − | 1 100 | x | ) | ( | 40 | + | 2 | x | ) | = | 2400 |
| Left side of the equation = | 2700 | ( | 1 | − | 1 100 | x | ) | + | 20 | ( | 1 | − | 1 100 | x | ) | ( | 40 | + | 2 | x | ) |
| 2700 | ( | 1 | − | 1 100 | x | ) | + | 20 | ( | 1 | − | 1 100 | x | ) | ( | 40 | + | 2 | x | ) | = | 2400 |
| Left side of the equation = | 2700 | × | 1 | − | 2700 | × | 1 100 | x | + | 20 | ( | 1 | − | 1 100 | x | ) | ( | 40 | + | 2 | x | ) |
| = | 2700 | − | 27 | x | + | 20 | ( | 1 | − | 1 100 | x | ) | ( | 40 | + | 2 | x | ) |
| = | 2700 | − | 27 | x | + | 20 | × | 1 | ( | 40 | + | 2 | x | ) | − | 20 | × | 1 100 | x | ( | 40 | + | 2 | x | ) |
| = | 2700 | − | 27 | x | + | 20 | ( | 40 | + | 2 | x | ) | − | 1 5 | x | ( | 40 | + | 2 | x | ) |
| = | 2700 | − | 27 | x | + | 20 | × | 40 | + | 20 | × | 2 | x | − | 1 5 | x | ( | 40 | + | 2 | x | ) |
| = | 2700 | − | 27 | x | + | 800 | + | 40 | x | − | 1 5 | x | ( | 40 | + | 2 | x | ) |
| = | 3500 | + | 13 | x | − | 1 5 | x | ( | 40 | + | 2 | x | ) |
| = | 3500 | + | 13 | x | − | 1 5 | x | × | 40 | − | 1 5 | x | × | 2 | x |
| = | 3500 | + | 13 | x | − | 8 | x | − | 2 5 | x | x |
| = | 3500 | + | 5 | x | − | 2 5 | x | x |
| 3500 | + | 5 | x | − | 2 5 | x | x | = | 2400 |