| ( | 80 100 | x | − | ( | x | − | 50 | ) | ) | = | ( | 50 | − | 30 | ) | × | 12 |
| Left side of the equation = | 80 100 | x | − | ( | x | − | 50 | ) |
| = | 80 100 | x | − | x | + | 50 |
| = | - | 1 5 | x | + | 50 |
| - | 1 5 | x | + | 50 | = | ( | 50 | − | 30 | ) | × | 12 |
| Right side of the equation = | 50 | × | 12 | − | 30 | × | 12 |
| = | 600 | − | 360 |
| = | 240 |
| - | 1 5 | x | + | 50 | = | 240 |
| - | 1 5 | x | = | 240 | − | 50 |
| - | 1 5 | x | = | 190 |
| - | 190 | = | 1 5 | x |
1 5 | x | = | - | 190 |
| x | = | - | 190 | ÷ | 1 5 |
| = | - | 190 | × | 5 |
| x | = | - | 950 |