| ( | 180 | + | x | ) | ÷ | ( | 180 | − | x | ) | = | 3 2 |
| 方程两边同时乘以: | ( | 180 | − | x | ) |
| ( | 180 | + | x | ) | = | 3 2 | ( | 180 | − | x | ) |
| 180 | + | x | = | 3 2 | ( | 180 | − | x | ) |
| 180 | + | x | = | 3 2 | × | 180 | − | 3 2 | x |
| 180 | + | x | = | 270 | − | 3 2 | x |
| x | + | 3 2 | x | = | 270 | − | 180 |
5 2 | x | = | 270 | − | 180 |
5 2 | x | = | 90 |
| x | = | 90 | ÷ | 5 2 |
| = | 90 | × | 2 5 |
| = | 18 | × | 2 |
| x | = | 36 |