| ( | x | − | 20 | ) | ÷ | x | − | 3 | ( | x | + | 20 | ) | ÷ | ( | x | + | 45 | ) | = | 1 |
| Multiply both sides of the equation by: | x |
| ( | x | − | 20 | ) | − | 3 | ( | x | + | 20 | ) | ÷ | ( | x | + | 45 | ) | × | x | = | 1 | x |
| x | − | 20 | − | 3 | ( | x | + | 20 | ) | ÷ | ( | x | + | 45 | ) | × | x | = | 1 | x |
| Multiply both sides of the equation by: | ( | x | + | 45 | ) |
| x | ( | x | + | 45 | ) | − | 20 | ( | x | + | 45 | ) | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | ( | x | + | 45 | ) |
| x | x | + | x | × | 45 | − | 20 | ( | x | + | 45 | ) | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | ( | x | + | 45 | ) |
| x | x | + | x | × | 45 | − | 20 | ( | x | + | 45 | ) | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | x | + | 1 | x | × | 45 |
| x | x | + | x | × | 45 | − | 20 | ( | x | + | 45 | ) | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | x | + | 45 | x |
| x | x | + | 45 | x | − | 20 | x | − | 20 | × | 45 | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | x | + | 45 | x |
| x | x | + | 45 | x | − | 20 | x | − | 900 | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | x | + | 45 | x |
| x | x | + | 25 | x | − | 900 | − | 3 | ( | x | + | 20 | ) | x | = | 1 | x | x | + | 45 | x |
| x | x | + | 25 | x | − | 900 | − | 3 | x | x | − | 3 | × | 20 | x | = | 1 | x | x | + | 45 | x |
| x | x | + | 25 | x | − | 900 | − | 3 | x | x | − | 60 | x | = | 1 | x | x | + | 45 | x |
| x | x | − | 35 | x | − | 900 | − | 3 | x | x | = | 1 | x | x | + | 45 | x |