| ( | x | × | 9 10 | ÷ | 12 | ) | + | ( | 1200 | × | 19 20 | ) | − | 1000 | = | 0 |
| Left side of the equation = | x | × | 9 10 | ÷ | 12 | + | ( | 1200 | × | 19 20 | ) | − | 1000 |
| = | x | × | 3 40 | + | ( | 1200 | × | 19 20 | ) | − | 1000 |
| = | 3 40 | x | + | 1200 | × | 19 20 | − | 1000 |
| = | 3 40 | x | + | 1140 | − | 1000 |
| = | 3 40 | x | + | 140 |
3 40 | x | + | 140 | = | 0 |
3 40 | x | = | 0 | − | 140 |
3 40 | x | = | - | 140 |
| x | = | - | 140 | ÷ | 3 40 |
| = | - | 140 | × | 40 3 |
| x | = | - | 5600 3 |
| x | = | - 1866.666667 |