9 10 | ( | 1200 | − | x | ) | + | 200 | + | 17 20 | ( | 500 | − | 200 | ) | + | 4 5 | ( | x | − | 500 | ) | = | 1098 |
| Left side of the equation = | 9 10 | × | 1200 | − | 9 10 | x | + | 200 | + | 17 20 | ( | 500 | − | 200 | ) | + | 4 5 | ( | x | − | 500 | ) |
| = | 1080 | − | 9 10 | x | + | 200 | + | 17 20 | ( | 500 | − | 200 | ) | + | 4 5 | ( | x | − | 500 | ) |
| = | 1280 | − | 9 10 | x | + | 17 20 | ( | 500 | − | 200 | ) | + | 4 5 | ( | x | − | 500 | ) |
| = | 1280 | − | 9 10 | x | + | 17 20 | × | 500 | − | 17 20 | × | 200 | + | 4 5 | ( | x | − | 500 | ) |
| = | 1280 | − | 9 10 | x | + | 425 | − | 170 | + | 4 5 | ( | x | − | 500 | ) |
| = | 1535 | − | 9 10 | x | + | 4 5 | ( | x | − | 500 | ) |
| = | 1535 | − | 9 10 | x | + | 4 5 | x | − | 4 5 | × | 500 |
| = | 1535 | − | 9 10 | x | + | 4 5 | x | − | 400 |
| = | 1135 | − | 1 10 | x |
| 1135 | − | 1 10 | x | = | 1098 |
| - | 1 10 | x | = | 1098 | − | 1135 |
| - | 1 10 | x | = | - | 37 |
| 37 | = | 1 10 | x |
1 10 | x | = | 37 |
| x | = | 37 | ÷ | 1 10 |
| = | 37 | × | 10 |
| x | = | 370 |