| 50 | x | − | 80 | ( | x | + | 300 | ) | = | 69500 |
| Left side of the equation = | 50 | x | − | 80 | x | − | 80 | × | 300 |
| = | 50 | x | − | 80 | x | − | 24000 |
| = | - | 30 | x | − | 24000 |
| - | 30 | x | − | 24000 | = | 69500 |
| - | 30 | x | = | 69500 | + | 24000 |
| - | 30 | x | = | 93500 |
| - | 93500 | = | 30 | x |
| 30 | x | = | - | 93500 |
| x | = | - | 93500 | ÷ | 30 |
| = | - | 93500 | × | 1 30 |
| = | - | 9350 | × | 1 3 |
| x | = | - | 9350 3 |
| x | = | - 3116.666667 |