| 90 | ( | 10000 | ÷ | x | ) | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 90 | ( | 10000 | ÷ | x | ) | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | = | 20000 |
| 90 | × | 10000 | ÷ | x | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 90 | ( | 10000 | ÷ | x | ) | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | = | 20000 |
| 900000 | ÷ | x | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 90 | ( | 10000 | ÷ | x | ) | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | = | 20000 |
| Multiply both sides of the equation by: | x |
| 900000 | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | x | + | 90 | ( | 10000 | ÷ | 1 | ) | × | 1 | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | = | 20000 | x |
| 900000 | + | 110 | × | 10000 | ÷ | 90 | × | x | − | 110 | × | 10000 | ÷ | x | × | x | + | 90 | ( | 10000 | ÷ | 1 | ) | × | 1 | = | 20000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | ÷ | x | × | x | + | 90 | ( | 10000 | ÷ | 1 | ) | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | = | 20000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | ÷ | 1 | × | 1 | + | 90 | × | 10000 | ÷ | 1 | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | = | 20000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | + | 900000 | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | = | 20000 | x |
| 700000 | + | 110000 9 | x | + | 110 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 90 | ) | x | = | 20000 | x |
| 700000 | + | 110000 9 | x | + | 110 | × | 20000 | ÷ | x | × | x | − | 110 | × | 10000 | ÷ | 90 | × | x | = | 20000 | x |
| 700000 | + | 110000 9 | x | + | 2200000 | ÷ | x | × | x | − | 110000 9 | x | = | 20000 | x |
| 700000 | + | 0 | x | + | 2200000 | ÷ | x | × | x | = | 20000 | x |
| - | 20000 | x | = | - | 700000 | − | 2200000 | ÷ | 1 | × | 1 |
| - | 20000 | x | = | - | 700000 | − | 2200000 |
| - | 20000 | x | = | - | 2900000 |
| 2900000 | = | 20000 | x |
| 20000 | x | = | 2900000 |
| x | = | 2900000 | ÷ | 20000 |
| = | 2900000 | × | 1 20000 |
| = | 145 | × | 1 |
| x | = | 145 |