| x | = | 7800000 | ÷ | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) |
| Multiply both sides of the equation by: | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) |
| x | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) | = | 7800000 |
| x | ( | 40 | + | 10 | ) | × | 10 | × | 500 | = | 7800000 |
| x | ( | 40 | + | 10 | ) | × | 5000 | = | 7800000 |
| x | × | 40 | × | 5000 | + | x | × | 10 | × | 5000 | = | 7800000 |
| x | × | 200000 | + | x | × | 50000 | = | 7800000 |
| 250000 | x | = | 7800000 |
| x | = | 7800000 | ÷ | 250000 |
| = | 7800000 | × | 1 250000 |
| = | 156 | × | 1 5 |
| x | = | 156 5 |
| x | = | 31.2 |