| 1200 | ÷ | ( | x | − | 50 | ) | = | 800 | − | ( | x | − | 60 | ) | × | 20 |
| Multiply both sides of the equation by: | ( | x | − | 50 | ) |
| 1200 | = | 800 | ( | x | − | 50 | ) | − | ( | x | − | 60 | ) | × | 20 | ( | x | − | 50 | ) |
| 1200 | = | 800 | x | − | 800 | × | 50 | − | ( | x | − | 60 | ) | × | 20 | ( | x | − | 50 | ) |
| 1200 | = | 800 | x | − | 40000 | − | ( | x | − | 60 | ) | × | 20 | ( | x | − | 50 | ) |
| 1200 | = | 800 | x | − | 40000 | − | x | × | 20 | ( | x | − | 50 | ) | + | 60 | × | 20 | ( | x | − | 50 | ) |
| 1200 | = | 800 | x | − | 40000 | − | x | × | 20 | ( | x | − | 50 | ) | + | 1200 | ( | x | − | 50 | ) |
| 1200 | = | 800 | x | − | 40000 | − | x | × | 20 | x | + | x | × | 20 | × | 50 | + | 1200 | ( | x | − | 50 | ) |
| 1200 | = | 800 | x | − | 40000 | − | x | × | 20 | x | + | x | × | 1000 | + | 1200 | ( | x | − | 50 | ) |
| 1200 | = | 1800 | x | − | 40000 | − | x | × | 20 | x | + | 1200 | ( | x | − | 50 | ) |
| 1200 | = | 1800 | x | − | 40000 | − | x | × | 20 | x | + | 1200 | x | − | 1200 | × | 50 |
| 1200 | = | 1800 | x | − | 40000 | − | x | × | 20 | x | + | 1200 | x | − | 60000 |
| 1200 | = | 3000 | x | − | 100000 | − | x | × | 20 | x |