| ( | 5 | ( | 10 | + | X | ) | + | 1 | × | 3 | + | 3 | × | 3 | ) | ÷ | ( | 16 | + | X | ) | = | 9 2 |
| 方程两边同时乘以: | ( | 16 | + | X | ) |
| ( | 5 | ( | 10 | + | X | ) | + | 1 | × | 3 | + | 3 | × | 3 | ) | = | 9 2 | ( | 16 | + | X | ) |
| 5 | ( | 10 | + | X | ) | + | 1 | × | 3 | + | 3 | × | 3 | = | 9 2 | ( | 16 | + | X | ) |
| 5 | ( | 10 | + | X | ) | + | 1 | × | 3 | + | 3 | × | 3 | = | 9 2 | × | 16 | + | 9 2 | X |
| 5 | ( | 10 | + | X | ) | + | 3 | + | 9 | = | 72 | + | 9 2 | X |
| 5 | ( | 10 | + | X | ) | + | 12 | = | 72 | + | 9 2 | X |
| 5 | × | 10 | + | 5 | X | + | 12 | = | 72 | + | 9 2 | X |
| 50 | + | 5 | X | + | 12 | = | 72 | + | 9 2 | X |
| 62 | + | 5 | X | = | 72 | + | 9 2 | X |
| 5 | X | − | 9 2 | X | = | 72 | − | 62 |
1 2 | X | = | 72 | − | 62 |
1 2 | X | = | 10 |
| X | = | 10 | ÷ | 1 2 |
| = | 10 | × | 2 |
| X | = | 20 |