| ( | x | − | 66 | ) | ( | 1 | + | 3 5 | ) | × | 9 10 | = | x |
| 方程左边 = | x | ( | 1 | + | 3 5 | ) | × | 9 10 | − | 66 | ( | 1 | + | 3 5 | ) | × | 9 10 |
| = | x | ( | 1 | + | 3 5 | ) | × | 9 10 | − | 297 5 | ( | 1 | + | 3 5 | ) |
| = | x | × | 1 | × | 9 10 | + | x | × | 3 5 | × | 9 10 | − | 297 5 | ( | 1 | + | 3 5 | ) |
| = | x | × | 9 10 | + | x | × | 27 50 | − | 297 5 | ( | 1 | + | 3 5 | ) |
| = | 36 25 | x | − | 297 5 | ( | 1 | + | 3 5 | ) |
| = | 36 25 | x | − | 297 5 | × | 1 | − | 297 5 | × | 3 5 |
| = | 36 25 | x | − | 297 5 | − | 891 25 |
| = | 36 25 | x | − | 2376 25 |
36 25 | x | − | 2376 25 | = | x |
36 25 | x | − | x | = | 2376 25 |
11 25 | x | = | 2376 25 |
| x | = | 2376 25 | ÷ | 11 25 |
| = | 2376 25 | × | 25 11 |
| = | 216 | × | 1 |
| x | = | 216 |