| 45 | ÷ | ( | x | ÷ | 2 | − | 45 | ) | = | ( | x | ÷ | 2 | + | 40 | ) | ÷ | ( | x | ÷ | 2 | + | x | ÷ | 2 | − | 40 | ) |
| Multiply both sides of the equation by: | ( | x | ÷ | 2 | − | 45 | ) | , | ( | x | ÷ | 2 | + | x | ÷ | 2 | − | 40 | ) |
| 45 | ( | x | ÷ | 2 | + | x | ÷ | 2 | − | 40 | ) | = | ( | x | ÷ | 2 | + | 40 | ) | ( | x | ÷ | 2 | − | 45 | ) |
| 45 | x | ÷ | 2 | + | 45 | x | ÷ | 2 | − | 45 | × | 40 | = | ( | x | ÷ | 2 | + | 40 | ) | ( | x | ÷ | 2 | − | 45 | ) |
| 45 | x | ÷ | 2 | + | 45 | x | ÷ | 2 | − | 45 | × | 40 | = | x | ÷ | 2 | × | ( | x | ÷ | 2 | − | 45 | ) | + | 40 | ( | x | ÷ | 2 | − | 45 | ) |
45 2 | x | + | 45 2 | x | − | 1800 | = | x | × | 1 2 | ( | x | ÷ | 2 | − | 45 | ) | + | 40 | ( | x | ÷ | 2 | − | 45 | ) |
| 45 | x | − | 1800 | = | x | × | 1 2 | ( | x | ÷ | 2 | − | 45 | ) | + | 40 | ( | x | ÷ | 2 | − | 45 | ) |
| 45 | x | − | 1800 | = | x | × | 1 2 | x | ÷ | 2 | − | x | × | 1 2 | × | 45 | + | 40 | ( | x | ÷ | 2 | − | 45 | ) |
| 45 | x | − | 1800 | = | x | × | 1 4 | x | − | x | × | 45 2 | + | 40 | ( | x | ÷ | 2 | − | 45 | ) |
| 45 | x | − | 1800 | = | x | × | 1 4 | x | − | 45 2 | x | + | 40 | x | ÷ | 2 | − | 40 | × | 45 |
| 45 | x | − | 1800 | = | x | × | 1 4 | x | − | 45 2 | x | + | 20 | x | − | 1800 |
| 45 | x | − | 1800 | = | x | × | 1 4 | x | − | 5 2 | x | − | 1800 |