| 2430 | ÷ | ( | 10 | x | ) | − | 3240 | ÷ | ( | 15 | x | ) | = | 30 |
| Multiply both sides of the equation by: | ( | 10 | x | ) |
| 2430 | − | 3240 | ÷ | ( | 15 | × | 1 | ) | × | ( | 10 | × | 1 | ) | = | 30 | ( | 10 | x | ) |
| 2430 | − | 3240 | ÷ | ( | 15 | × | 1 | ) | × | 10 | × | 1 | = | 30 | ( | 10 | x | ) |
| 2430 | − | 3240 | ÷ | ( | 15 | × | 1 | ) | × | 10 | × | 1 | = | 30 | × | 10 | x |
| 2430 | − | 32400 | ÷ | ( | 15 | × | 1 | ) | = | 300 | x |
| Multiply both sides of the equation by: | ( | 15 | × | 1 | ) |
| 2430 | ( | 15 | × | 1 | ) | − | 32400 | = | 300 | x | ( | 15 | × | 1 | ) |
| 2430 | × | 15 | × | 1 | − | 32400 | = | 300 | x | ( | 15 | × | 1 | ) |
| 2430 | × | 15 | × | 1 | − | 32400 | = | 300 | x | × | 15 | × | 1 |
| 36450 | − | 32400 | = | 4500 | x |
| 4050 | = | 4500 | x |
| 4500 | x | = | 4050 |
| x | = | 4050 | ÷ | 4500 |
| = | 4050 | × | 1 4500 |
| = | 9 | × | 1 10 |
| x | = | 9 10 |
| x | = | 0.9 |