| ( | 476 | + | a | ) | ÷ | ( | 1107 | + | a | ) | = | 3 10 |
| 方程两边同时乘以: | ( | 1107 | + | a | ) |
| ( | 476 | + | a | ) | = | 3 10 | ( | 1107 | + | a | ) |
| 476 | + | a | = | 3 10 | ( | 1107 | + | a | ) |
| 476 | + | a | = | 3 10 | × | 1107 | + | 3 10 | a |
| 476 | + | a | = | 3321 10 | + | 3 10 | a |
| a | − | 3 10 | a | = | 3321 10 | − | 476 |
7 10 | a | = | 3321 10 | − | 476 |
7 10 | a | = | - | 1439 10 |
| a | = | - | 1439 10 | ÷ | 7 10 |
| = | - | 1439 10 | × | 10 7 |
| = | - | 1439 | × | 1 7 |
| a | = | - | 1439 7 |
| a | = | - 205.571429 |