| ( | x | − | 4 | ) | × | 50 | = | ( | x | − | 6 | ) | × | 30 |
| Left side of the equation = | x | × | 50 | − | 4 | × | 50 |
| = | x | × | 50 | − | 200 |
| 50 | x | − | 200 | = | ( | x | − | 6 | ) | × | 30 |
| Right side of the equation = | x | × | 30 | − | 6 | × | 30 |
| = | x | × | 30 | − | 180 |
| 50 | x | − | 200 | = | 30 | x | − | 180 |
| 50 | x | − | 30 | x | = | - | 180 | + | 200 |
| 20 | x | = | - | 180 | + | 200 |
| 20 | x | = | 20 |
| x | = | 20 | ÷ | 20 |
| = | 20 | × | 1 20 |
| = | 1 | × | 1 |
| x | = | 1 |