| ( | 840 | − | x | ) | ÷ | ( | 500 | − | x | ) | = | 24 | ÷ | 7 |
| Multiply both sides of the equation by: | ( | 500 | − | x | ) |
| ( | 840 | − | x | ) | = | 24 | ÷ | 7 | × | ( | 500 | − | x | ) |
| 840 | − | x | = | 24 | ÷ | 7 | × | ( | 500 | − | x | ) |
| 840 | − | x | = | 24 | ÷ | 7 | × | 500 | − | 24 | ÷ | 7 | × | x |
| 840 | − | x | = | 12000 7 | − | 24 7 | x |
| - | x | + | 24 7 | x | = | 12000 7 | − | 840 |
17 7 | x | = | 12000 7 | − | 840 |
17 7 | x | = | 6120 7 |
| x | = | 6120 7 | ÷ | 17 7 |
| = | 6120 7 | × | 7 17 |
| = | 360 | × | 1 |
| x | = | 360 |