| ( | 6 | + | 1 2 | ) | ( | 400 | − | 10 | X | ) | − | 40 | X | − | 1600 | = | 1175 |
| Left side of the equation = | 6 | ( | 400 | − | 10 | X | ) | + | 1 2 | ( | 400 | − | 10 | X | ) | − | 40 | X | − | 1600 |
| = | 6 | × | 400 | − | 6 | × | 10 | X | + | 1 2 | ( | 400 | − | 10 | X | ) | − | 40 | X | − | 1600 |
| = | 2400 | − | 60 | X | + | 1 2 | ( | 400 | − | 10 | X | ) | − | 40 | X | − | 1600 |
| = | 800 | − | 100 | X | + | 1 2 | ( | 400 | − | 10 | X | ) |
| = | 800 | − | 100 | X | + | 1 2 | × | 400 | − | 1 2 | × | 10 | X |
| = | 800 | − | 100 | X | + | 200 | − | 5 | X |
| = | 1000 | − | 105 | X |
| 1000 | − | 105 | X | = | 1175 |
| - | 105 | X | = | 1175 | − | 1000 |
| - | 105 | X | = | 175 |
| - | 175 | = | 105 | X |
| 105 | X | = | - | 175 |
| X | = | - | 175 | ÷ | 105 |
| = | - | 175 | × | 1 105 |
| = | - | 5 | × | 1 3 |
| X | = | - | 5 3 |
| X | = | - 1.666667 |