| ( | 360 | ÷ | x | ) | ( | 14 | ÷ | 15 | ) | = | 420 | ÷ | ( | x | + | 3 | ) |
| Multiply both sides of the equation by: | ( | x | + | 3 | ) |
| ( | 360 | ÷ | x | ) | ( | 14 | ÷ | 15 | ) | ( | x | + | 3 | ) | = | 420 |
| 360 | ÷ | x | × | ( | 14 | ÷ | 15 | ) | ( | x | + | 3 | ) | = | 420 |
| Multiply both sides of the equation by: | x |
| 360 | ( | 14 | ÷ | 15 | ) | ( | x | + | 3 | ) | = | 420 | x |
| 360 | × | 14 | ÷ | 15 | × | ( | x | + | 3 | ) | = | 420 | x |
| 336 | ( | x | + | 3 | ) | = | 420 | x |
| 336 | x | + | 336 | × | 3 | = | 420 | x |
| 336 | x | + | 1008 | = | 420 | x |
| 336 | x | − | 420 | x | = | - | 1008 |
| - | 84 | x | = | - | 1008 |
| 1008 | = | 84 | x |
| 84 | x | = | 1008 |
| x | = | 1008 | ÷ | 84 |
| = | 1008 | × | 1 84 |
| = | 12 | × | 1 |
| x | = | 12 |