| 120 | ( | 10000 | ÷ | x | ) | + | 130 | ( | 10000 | ÷ | 120 | − | 10000 | ÷ | x | ) | + | 60 | ( | 10000 | ÷ | x | ) | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | = | 20000 |
| 120 | × | 10000 | ÷ | x | + | 130 | ( | 10000 | ÷ | 120 | − | 10000 | ÷ | x | ) | + | 60 | ( | 10000 | ÷ | x | ) | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | = | 20000 |
| 1200000 | ÷ | x | + | 130 | ( | 10000 | ÷ | 120 | − | 10000 | ÷ | x | ) | + | 60 | ( | 10000 | ÷ | x | ) | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | = | 20000 |
| Multiply both sides of the equation by: | x |
| 1200000 | + | 130 | ( | 10000 | ÷ | 120 | − | 10000 | ÷ | x | ) | x | + | 60 | ( | 10000 | ÷ | 1 | ) | × | 1 | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | x | = | 20000 | x |
| 1200000 | + | 130 | × | 10000 | ÷ | 120 | × | x | − | 130 | × | 10000 | ÷ | x | × | x | + | 60 | ( | 10000 | ÷ | 1 | ) | × | 1 | = | 20000 | x |
| 1200000 | + | 32500 3 | x | − | 1300000 | ÷ | x | × | x | + | 60 | ( | 10000 | ÷ | 1 | ) | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | x | = | 20000 | x |
| 1200000 | + | 32500 3 | x | − | 1300000 | ÷ | 1 | × | 1 | + | 60 | × | 10000 | ÷ | 1 | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | x | = | 20000 | x |
| 1200000 | + | 32500 3 | x | − | 1300000 | + | 600000 | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | x | = | 20000 | x |
| 500000 | + | 32500 3 | x | + | 80 | ( | 10000 | ÷ | 60 | − | 10000 | ÷ | x | ) | x | = | 20000 | x |
| 500000 | + | 32500 3 | x | + | 80 | × | 10000 | ÷ | 60 | × | x | − | 80 | × | 10000 | ÷ | x | × | x | = | 20000 | x |
| 500000 | + | 32500 3 | x | + | 40000 3 | x | − | 800000 | ÷ | x | × | x | = | 20000 | x |
| 500000 | + | 72500 3 | x | − | 800000 | ÷ | x | × | x | = | 20000 | x |
72500 3 | x | − | 20000 | x | = | - | 500000 | + | 800000 | ÷ | 1 | × | 1 |
72500 3 | x | − | 20000 | x | = | - | 500000 | + | 800000 |
12500 3 | x | = | - | 500000 | + | 800000 |
12500 3 | x | = | 300000 |
| x | = | 300000 | ÷ | 12500 3 |
| = | 300000 | × | 3 12500 |
| = | 24 | × | 3 |
| x | = | 72 |