| ( | 280 | × | 49 4 | ) | ÷ | ( | 49 4 | + | 4 | z | + | 4 | z | z | ) | = | 60 |
| Multiply both sides of the equation by: | ( | 49 4 | + | 4 | z | + | 4 | z | z | ) |
| ( | 280 | × | 49 4 | ) | = | 60 | ( | 49 4 | + | 4 | z | + | 4 | z | z | ) |
| 280 | × | 49 4 | = | 60 | ( | 49 4 | + | 4 | z | + | 4 | z | z | ) |
| 280 | × | 49 4 | = | 60 | × | 49 4 | + | 60 | × | 4 | z | + | 60 | × | 4 | z | z |
| 3430 | = | 735 | + | 240 | z | + | 240 | z | z |