| ( | 1 | ÷ | 3 | ) | x | − | ( | 200 | − | x | ) | × | 1 10 | = | 19 |
| Left side of the equation = | 1 | ÷ | 3 | × | x | − | ( | 200 | − | x | ) | × | 1 10 |
| = | 1 3 | x | − | ( | 200 | − | x | ) | × | 1 10 |
| = | 1 3 | x | − | 200 | × | 1 10 | + | x | × | 1 10 |
| = | 1 3 | x | − | 20 | + | x | × | 1 10 |
| = | 13 30 | x | − | 20 |
13 30 | x | − | 20 | = | 19 |
13 30 | x | = | 19 | + | 20 |
13 30 | x | = | 39 |
| x | = | 39 | ÷ | 13 30 |
| = | 39 | × | 30 13 |
| = | 3 | × | 30 |
| x | = | 90 |