| ( | 100 | + | 84 | m | ) | ÷ | ( | m | + | 1 | ) | = | 86 |
| 方程两边同时乘以: | ( | m | + | 1 | ) |
| ( | 100 | + | 84 | m | ) | = | 86 | ( | m | + | 1 | ) |
| 100 | + | 84 | m | = | 86 | ( | m | + | 1 | ) |
| 100 | + | 84 | m | = | 86 | m | + | 86 | × | 1 |
| 100 | + | 84 | m | = | 86 | m | + | 86 |
| 84 | m | − | 86 | m | = | 86 | − | 100 |
| - | 2 | m | = | 86 | − | 100 |
| - | 2 | m | = | - | 14 |
| 14 | = | 2 | m |
| 2 | m | = | 14 |
| m | = | 14 | ÷ | 2 |
| = | 14 | × | 1 2 |
| = | 7 | × | 1 |
| m | = | 7 |