| ( | x | + | 695 | ) | ÷ | ( | 879 | + | x | ) | = | 80 100 |
| 方程两边同时乘以: | ( | 879 | + | x | ) |
| ( | x | + | 695 | ) | = | 80 100 | ( | 879 | + | x | ) |
| x | + | 695 | = | 80 100 | ( | 879 | + | x | ) |
| x | + | 695 | = | 80 100 | × | 879 | + | 80 100 | x |
| x | + | 695 | = | 3516 5 | + | 80 100 | x |
| x | − | 80 100 | x | = | 3516 5 | − | 695 |
1 5 | x | = | 3516 5 | − | 695 |
1 5 | x | = | 41 5 |
| x | = | 41 5 | ÷ | 1 5 |
| = | 41 5 | × | 5 |
| = | 41 | × | 1 |
| x | = | 41 |