| 90 | ( | 10000 | ÷ | x | ) | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 90 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | + | 110 | ( | 10000 | ÷ | x | ) | = | 20000 |
| 90 | × | 10000 | ÷ | x | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 90 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | + | 110 | ( | 10000 | ÷ | x | ) | = | 20000 |
| 900000 | ÷ | x | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 90 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | + | 110 | ( | 10000 | ÷ | x | ) | = | 20000 |
| Multiply both sides of the equation by: | x |
| 900000 | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | x | + | 90 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | + | 110 | ( | 10000 | ÷ | 1 | ) | × | 1 | = | 20000 | x |
| 900000 | + | 110 | × | 10000 | ÷ | 90 | × | x | − | 110 | × | 10000 | ÷ | x | × | x | + | 90 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | = | 20000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | ÷ | x | × | x | + | 90 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | + | 110 | ( | 10000 | ÷ | 1 | ) | = | 20000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | ÷ | 1 | × | 1 | + | 90 | × | 20000 | ÷ | x | × | x | − | 90 | × | 10000 | = | 20000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | + | 1800000 | ÷ | x | × | x | − | 10000 | x | + | 110 | ( | 10000 | ÷ | 1 | ) | = | 20000 | x |
| - | 200000 | + | 20000 9 | x | + | 1800000 | ÷ | x | × | x | + | 110 | ( | 10000 | ÷ | 1 | ) | = | 20000 | x |
| - | 200000 | + | 20000 9 | x | + | 1800000 | ÷ | 1 | × | 1 | + | 110 | × | 10000 | ÷ | 1 | = | 20000 | x |
| - | 200000 | + | 20000 9 | x | + | 1800000 | + | 1100000 | = | 20000 | x |
| 2700000 | + | 20000 9 | x | = | 20000 | x |
20000 9 | x | − | 20000 | x | = | - | 2700000 |
| - | 160000 9 | x | = | - | 2700000 |
| 2700000 | = | 160000 9 | x |
160000 9 | x | = | 2700000 |
| x | = | 2700000 | ÷ | 160000 9 |
| = | 2700000 | × | 9 160000 |
| = | 135 | × | 9 8 |
| x | = | 1215 8 |
| x | = | 151.875 |