| 305 | × | 7 20 | + | X | = | ( | 55 | ÷ | 130 | ) | ( | 305 | + | 3 2 | X | ) |
| 方程左边 = | 427 4 | + | X |
427 4 | + | X | = | ( | 55 | ÷ | 130 | ) | ( | 305 | + | 3 2 | X | ) |
| 方程右边 = | 55 | ÷ | 130 | × | ( | 305 | + | 3 2 | X | ) |
| = | 11 26 | ( | 305 | + | 3 2 | X | ) |
| = | 11 26 | × | 305 | + | 11 26 | × | 3 2 | X |
| = | 3355 26 | + | 33 52 | X |
427 4 | + | X | = | 3355 26 | + | 33 52 | X |
| X | − | 33 52 | X | = | 3355 26 | − | 427 4 |
19 52 | X | = | 3355 26 | − | 427 4 |
19 52 | X | = | 1159 52 |
| X | = | 1159 52 | ÷ | 19 52 |
| = | 1159 52 | × | 52 19 |
| = | 61 | × | 1 |
| X | = | 61 |