| ( | 7 20 | − | a | ) | ( | 1 4 | − | a | ) | ÷ | ( | 1 10 | + | a | ) | = | 5 8 |
| Multiply both sides of the equation by: | ( | 1 10 | + | a | ) |
| ( | 7 20 | − | a | ) | ( | 1 4 | − | a | ) | = | 5 8 | ( | 1 10 | + | a | ) |
7 20 | ( | 1 4 | − | a | ) | − | a | ( | 1 4 | − | a | ) | = | 5 8 | ( | 1 10 | + | a | ) |
7 20 | ( | 1 4 | − | a | ) | − | a | ( | 1 4 | − | a | ) | = | 5 8 | × | 1 10 | + | 5 8 | a |
7 20 | ( | 1 4 | − | a | ) | − | a | ( | 1 4 | − | a | ) | = | 1 16 | + | 5 8 | a |
7 20 | × | 1 4 | − | 7 20 | a | − | a | ( | 1 4 | − | a | ) | = | 1 16 | + | 5 8 | a |
7 80 | − | 7 20 | a | − | a | ( | 1 4 | − | a | ) | = | 1 16 | + | 5 8 | a |
7 80 | − | 7 20 | a | − | a | × | 1 4 | + | a | a | = | 1 16 | + | 5 8 | a |
7 80 | − | 3 5 | a | + | a | a | = | 1 16 | + | 5 8 | a |