| 90 | ( | 10000 | ÷ | x | ) | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 60 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 60 | ) | + | 80 | ( | 20000 | ÷ | x | ) | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | + | 80 | ( | 10000 | ÷ | x | ) | = | 30000 |
| 90 | × | 10000 | ÷ | x | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 60 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 60 | ) | + | 80 | ( | 20000 | ÷ | x | ) | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | + | 80 | = | 30000 |
| 900000 | ÷ | x | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | + | 60 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 60 | ) | + | 80 | ( | 20000 | ÷ | x | ) | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | + | 80 | ( | 10000 | ÷ | x | ) | = | 30000 |
| Multiply both sides of the equation by: | x |
| 900000 | + | 110 | ( | 10000 | ÷ | 90 | − | 10000 | ÷ | x | ) | x | + | 60 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | + | 80 | ( | 20000 | ÷ | 1 | ) | × | 1 | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | = | 30000 | x |
| 900000 | + | 110 | × | 10000 | ÷ | 90 | × | x | − | 110 | × | 10000 | ÷ | x | × | x | + | 60 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | = | 30000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | ÷ | x | × | x | + | 60 | ( | 20000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | + | 80 | ( | 20000 | ÷ | 1 | ) | + | 60 | = | 30000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | ÷ | 1 | × | 1 | + | 60 | × | 20000 | ÷ | x | × | x | − | 60 | × | 10000 | = | 30000 | x |
| 900000 | + | 110000 9 | x | − | 1100000 | + | 1200000 | ÷ | x | × | x | − | 10000 | x | + | 80 | ( | 20000 | ÷ | 1 | ) | + | 60 | = | 30000 | x |
| - | 200000 | + | 20000 9 | x | + | 1200000 | ÷ | x | × | x | + | 80 | ( | 20000 | ÷ | 1 | ) | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | + | 80 | = | 30000 | x |
| - | 200000 | + | 20000 9 | x | + | 1200000 | ÷ | 1 | × | 1 | + | 80 | × | 20000 | ÷ | 1 | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | = | 30000 | x |
| - | 200000 | + | 20000 9 | x | + | 1200000 | + | 1600000 | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | + | 80 | ( | 10000 | ÷ | 1 | ) | = | 30000 | x |
| 2600000 | + | 20000 9 | x | + | 60 | ( | 30000 | ÷ | x | − | 10000 | ÷ | 60 | ) | x | + | 80 | ( | 10000 | ÷ | 1 | ) | = | 30000 | x |
| 2600000 | + | 20000 9 | x | + | 60 | × | 30000 | ÷ | x | × | x | − | 60 | × | 10000 | ÷ | 60 | × | x | + | 80 | = | 30000 | x |
| 2600000 | + | 20000 9 | x | + | 1800000 | ÷ | x | × | x | − | 10000 | x | + | 80 | ( | 10000 | ÷ | 1 | ) | = | 30000 | x |
| 2600000 | − | 70000 9 | x | + | 1800000 | ÷ | x | × | x | + | 80 | ( | 10000 | ÷ | 1 | ) | = | 30000 | x |
| 2600000 | − | 70000 9 | x | + | 1800000 | ÷ | 1 | × | 1 | + | 80 | × | 10000 | ÷ | 1 | = | 30000 | x |
| 2600000 | − | 70000 9 | x | + | 1800000 | + | 800000 | = | 30000 | x |
| 5200000 | − | 70000 9 | x | = | 30000 | x |
| - | 70000 9 | x | − | 30000 | x | = | - | 5200000 |
| - | 340000 9 | x | = | - | 5200000 |
| 5200000 | = | 340000 9 | x |
340000 9 | x | = | 5200000 |
| x | = | 5200000 | ÷ | 340000 9 |
| = | 5200000 | × | 9 340000 |
| = | 260 | × | 9 17 |
| x | = | 2340 17 |
| x | = | 137.647059 |