| ( | 3 20 | + | x | ) | ÷ | ( | 1 20 | − | x | ) | ÷ | ( | 1 200 | − | x | ) | = | 353000000000 |
| Multiply both sides of the equation by: | ( | 1 20 | − | x | ) |
| ( | 3 20 | + | x | ) | ÷ | ( | 1 200 | − | x | ) | = | 353000000000 | ( | 1 20 | − | x | ) |
3 20 | ÷ | ( | 1 200 | − | x | ) | + | x | ÷ | ( | 1 200 | − | x | ) | = | 353000000000 | ( | 1 20 | − | x | ) |
3 20 | ÷ | ( | 1 200 | − | x | ) | + | x | ÷ | ( | 1 200 | − | x | ) | = | 353000000000 | × | 1 20 | − | 353000000000 | x |