| 20 | x | + | 30 | ( | ( | 4 | ÷ | ( | 3 | x | ) | ) | ) | = | 540 |
| 20 | x | + | 30 | ( | 4 | ÷ | ( | 3 | x | ) | ) | = | 540 |
| 20 | x | + | 30 | × | 4 | ÷ | ( | 3 | x | ) | = | 540 |
| 20 | x | + | 120 | ÷ | ( | 3 | x | ) | = | 540 |
| Multiply both sides of the equation by: | ( | 3 | x | ) |
| 20 | x | ( | 3 | x | ) | + | 120 | = | 540 | ( | 3 | x | ) |
| 20 | x | × | 3 | x | + | 120 | = | 540 | ( | 3 | x | ) |
| 20 | x | × | 3 | x | + | 120 | = | 540 | × | 3 | x |
| 60 | x | x | + | 120 | = | 1620 | x |