| 1600 | − | ( | 400 | − | 10 | x | ) | ( | 6 | + | 1 2 | x | ) | − | 40 | x | = | 1175 |
| Left side of the equation = | 1600 | − | 400 | ( | 6 | + | 1 2 | x | ) | + | 10 | x | ( | 6 | + | 1 2 | x | ) | − | 40 | x |
| = | 1600 | − | 400 | × | 6 | − | 400 | × | 1 2 | x | + | 10 | x | ( | 6 | + | 1 2 | x | ) | − | 40 | x |
| = | 1600 | − | 2400 | − | 200 | x | + | 10 | x | ( | 6 | + | 1 2 | x | ) | − | 40 | x |
| = | - | 800 | − | 240 | x | + | 10 | x | ( | 6 | + | 1 2 | x | ) |
| = | - | 800 | − | 240 | x | + | 10 | x | × | 6 | + | 10 | x | × | 1 2 | x |
| = | - | 800 | − | 240 | x | + | 60 | x | + | 5 | x | x |
| = | - | 800 | − | 180 | x | + | 5 | x | x |
| - | 800 | − | 180 | x | + | 5 | x | x | = | 1175 |