| 1 | ÷ | ( | d | + | 20 | ) | = | 1 | ÷ | d | + | 2 | ÷ | ( | d | + | 12 | ) |
| Multiply both sides of the equation by: | ( | d | + | 20 | ) | , | d |
| 1 | d | = | 1 | ( | d | + | 20 | ) | + | 2 | ÷ | ( | d | + | 12 | ) | × | ( | d | + | 20 | ) | d |
| 1 | d | = | 1 | d | + | 1 | × | 20 | + | 2 | ÷ | ( | d | + | 12 | ) | × | ( | d | + | 20 | ) | d |
| 1 | d | = | 1 | d | + | 20 | + | 2 | ÷ | ( | d | + | 12 | ) | × | ( | d | + | 20 | ) | d |
| Multiply both sides of the equation by: | ( | d | + | 12 | ) |
| 1 | d | ( | d | + | 12 | ) | = | 1 | d | ( | d | + | 12 | ) | + | 20 | ( | d | + | 12 | ) | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 1 | d | × | 12 | = | 1 | d | ( | d | + | 12 | ) | + | 20 | ( | d | + | 12 | ) | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 1 | d | × | 12 | = | 1 | d | d | + | 1 | d | × | 12 | + | 20 | ( | d | + | 12 | ) | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 12 | d | + | 20 | ( | d | + | 12 | ) | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 12 | d | + | 20 | d | + | 20 | × | 12 | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 12 | d | + | 20 | d | + | 240 | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 32 | d | + | 240 | + | 2 | ( | d | + | 20 | ) | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 32 | d | + | 240 | + | 2 | d | d | + | 2 | × | 20 | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 32 | d | + | 240 | + | 2 | d | d | + | 40 | d |
| 1 | d | d | + | 12 | d | = | 1 | d | d | + | 72 | d | + | 240 | + | 2 | d | d |