| 20 | + | 99 100 | x | × | 10 | ÷ | ( | 100 | − | 1 4 | x | ) | − | 99 100 | x | − | 100 | × | 10 | ÷ | ( | 100 | − | 1 4 | x | ) | = | 0 |
| 方程两边同时乘以: | ( | 100 | − | 1 4 | x | ) |
| 20 | ( | 100 | − | 1 4 | x | ) | + | 99 100 | x | × | 10 | − | 99 100 | x | ( | 100 | − | 1 4 | x | ) | − | 100 | × | 10 | = | 0 |
| 20 | × | 100 | − | 20 | × | 1 4 | x | + | 99 100 | x | × | 10 | − | 99 100 | x | ( | 100 | − | 1 4 | x | ) | − | 100 | = | 0 |
| 2000 | − | 5 | x | + | 99 10 | x | − | 99 100 | x | ( | 100 | − | 1 4 | x | ) | − | 1000 | = | 0 |
| 1000 | + | 49 10 | x | − | 99 100 | x | ( | 100 | − | 1 4 | x | ) | = | 0 |
| 1000 | + | 49 10 | x | − | 99 100 | x | × | 100 | + | 99 100 | x | × | 1 4 | x | = | 0 |
| 1000 | + | 49 10 | x | − | 99 | x | + | 99 400 | x | x | = | 0 |
| 1000 | − | 941 10 | x | + | 99 400 | x | x | = | 0 |