| 300 | + | 6 5 | x | − | ( | 4 5 | x | + | 240 | ) | − | 100 | = | 600 |
| Left side of the equation = | 200 | + | 6 5 | x | − | ( | 4 5 | x | + | 240 | ) |
| 200 | + | 6 5 | x | − | ( | 4 5 | x | + | 240 | ) | = | 600 |
| Left side of the equation = | 200 | + | 6 5 | x | − | 4 5 | x | − | 240 |
| = | - | 40 | + | 2 5 | x |
| - | 40 | + | 2 5 | x | = | 600 |
2 5 | x | = | 600 | + | 40 |
2 5 | x | = | 640 |
| x | = | 640 | ÷ | 2 5 |
| = | 640 | × | 5 2 |
| = | 320 | × | 5 |
| x | = | 1600 |