| ( | ( | x | − | 80 | ) | ( | 1 | − | 25 100 | ) | ) | ÷ | ( | 4000 | + | 200 | ) | = | ( | ( | x | − | 160 | ) | ( | 1 | − | 25 100 | ) | ) | ÷ | 4000 |
| 方程两边同时乘以: | ( | 4000 | + | 200 | ) |
| ( | ( | x | − | 80 | ) | ( | 1 | − | 25 100 | ) | ) | = | ( | ( | x | − | 160 | ) | ( | 1 | − | 25 100 | ) | ) | ÷ | 4000 | × | ( | 4000 | + | 200 | ) |
| ( | x | − | 80 | ) | ( | 1 | − | 25 100 | ) | = | ( | ( | x | − | 160 | ) | ( | 1 | − | 25 100 | ) | ) | ÷ | 4000 | × | ( | 4000 | + | 200 | ) |
| ( | x | − | 80 | ) | ( | 1 | − | 25 100 | ) | = | ( | x | − | 160 | ) | ( | 1 | − | 25 100 | ) | ÷ | 4000 | × | ( | 4000 | + | 200 | ) |
| x | ( | 1 | − | 25 100 | ) | − | 80 | ( | 1 | − | 25 100 | ) | = | ( | x | − | 160 | ) | ( | 1 | − | 25 100 | ) | × | 1 4000 | ( | 4000 | + | 200 | ) |
| x | ( | 1 | − | 25 100 | ) | − | 80 | ( | 1 | − | 25 100 | ) | = | x | ( | 1 | − | 25 100 | ) | × | 1 4000 | ( | 4000 | + | 200 | ) | − | 160 | ( | 1 | − | 25 100 | ) | × | 1 4000 | ( | 4000 | + | 200 | ) |
| x | ( | 1 | − | 25 100 | ) | − | 80 | ( | 1 | − | 25 100 | ) | = | x | ( | 1 | − | 25 100 | ) | × | 1 4000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
| x | × | 1 | − | x | × | 25 100 | − | 80 | ( | 1 | − | 25 100 | ) | = | x | ( | 1 | − | 25 100 | ) | × | 1 4000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
| x | × | 1 | − | x | × | 25 100 | − | 80 | ( | 1 | − | 25 100 | ) | = | x | × | 1 | × | 1 4000 | ( | 4000 | + | 200 | ) | − | x | × | 25 100 | × | 1 4000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
| x | × | 1 | − | x | × | 25 100 | − | 80 | ( | 1 | − | 25 100 | ) | = | x | × | 1 4000 | ( | 4000 | + | 200 | ) | − | x | × | 1 16000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 80 | ( | 1 | − | 25 100 | ) | = | x | × | 1 4000 | ( | 4000 | + | 200 | ) | − | x | × | 1 16000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 80 | × | 1 | + | 80 | × | 25 100 | = | x | × | 1 4000 | ( | 4000 | + | 200 | ) | − | x | × | 1 16000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 80 | × | 1 | + | 80 | × | 25 100 | = | x | × | 1 4000 | × | 4000 | + | x | × | 1 4000 | × | 200 | − | x | × | 1 16000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 80 | + | 20 | = | x | × | 1 | + | x | × | 1 20 | − | x | × | 1 16000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 21 20 | x | − | x | × | 1 16000 | ( | 4000 | + | 200 | ) | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 21 20 | x | − | x | × | 1 16000 | × | 4000 | − | x | × | 1 16000 | × | 200 | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 21 20 | x | − | x | × | 1 4 | − | x | × | 1 80 | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 1 25 | ( | 1 | − | 25 100 | ) | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 1 25 | × | 1 | ( | 4000 | + | 200 | ) | + | 1 25 | × | 25 100 | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 1 25 | ( | 4000 | + | 200 | ) | + | 1 100 | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 1 25 | × | 4000 | − | 1 25 | × | 200 | + | 1 100 | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 160 | − | 8 | + | 1 100 | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 168 | + | 1 100 | ( | 4000 | + | 200 | ) |
3 4 | x | − | 60 | = | 63 80 | x | − | 168 | + | 1 100 | × | 4000 | + | 1 100 | × | 200 |
3 4 | x | − | 60 | = | 63 80 | x | − | 168 | + | 40 | + | 2 |
3 4 | x | − | 60 | = | 63 80 | x | − | 126 |
3 4 | x | − | 60 | = | 63 80 | x | − | 126 |
3 4 | x | − | 63 80 | x | = | - | 126 | + | 60 |
| - | 3 80 | x | = | - | 126 | + | 60 |
| - | 3 80 | x | = | - | 66 |
| 66 | = | 3 80 | x |
3 80 | x | = | 66 |
| x | = | 66 | ÷ | 3 80 |
| = | 66 | × | 80 3 |
| = | 22 | × | 80 |
| x | = | 1760 |