| ( | 118 | + | X | ) | ÷ | ( | 132 | + | X | ) | = | 9 10 |
| 方程两边同时乘以: | ( | 132 | + | X | ) |
| ( | 118 | + | X | ) | = | 9 10 | ( | 132 | + | X | ) |
| 118 | + | X | = | 9 10 | ( | 132 | + | X | ) |
| 118 | + | X | = | 9 10 | × | 132 | + | 9 10 | X |
| 118 | + | X | = | 594 5 | + | 9 10 | X |
| X | − | 9 10 | X | = | 594 5 | − | 118 |
1 10 | X | = | 594 5 | − | 118 |
1 10 | X | = | 4 5 |
| X | = | 4 5 | ÷ | 1 10 |
| = | 4 5 | × | 10 |
| = | 4 | × | 2 |
| X | = | 8 |