| ( | 340 | + | X | ) | × | 3 5 | = | 340 | + | X | − | 240 |
| Left side of the equation = | 340 | × | 3 5 | + | X | × | 3 5 |
| = | 204 | + | X | × | 3 5 |
| 204 | + | 3 5 | X | = | 340 | + | X | − | 240 |
| Right side of the equation = | 100 | + | X |
| 204 | + | 3 5 | X | = | 100 | + | X |
3 5 | X | − | X | = | 100 | − | 204 |
| - | 2 5 | X | = | 100 | − | 204 |
| - | 2 5 | X | = | - | 104 |
| 104 | = | 2 5 | X |
2 5 | X | = | 104 |
| X | = | 104 | ÷ | 2 5 |
| = | 104 | × | 5 2 |
| = | 52 | × | 5 |
| X | = | 260 |