| ( | 99 | − | x | ) | ÷ | ( | 110 | − | x | ) | = | ( | 98 | − | x | ) | ÷ | ( | 989 10 | − | x | ) |
| 方程两边同时乘以: | ( | 110 | − | x | ) | , | ( | 989 10 | − | x | ) |
| ( | 99 | − | x | ) | ( | 989 10 | − | x | ) | = | ( | 98 | − | x | ) | ( | 110 | − | x | ) |
| 99 | ( | 989 10 | − | x | ) | − | x | ( | 989 10 | − | x | ) | = | ( | 98 | − | x | ) | ( | 110 | − | x | ) |
| 99 | ( | 989 10 | − | x | ) | − | x | ( | 989 10 | − | x | ) | = | 98 | ( | 110 | − | x | ) | − | x | ( | 110 | − | x | ) |
| 99 | × | 989 10 | − | 99 | x | − | x | ( | 989 10 | − | x | ) | = | 98 | ( | 110 | − | x | ) | − | x | ( | 110 | − | x | ) |
| 99 | × | 989 10 | − | 99 | x | − | x | ( | 989 10 | − | x | ) | = | 98 | × | 110 | − | 98 | x | − | x | ( | 110 | − | x | ) |
97911 10 | − | 99 | x | − | x | ( | 989 10 | − | x | ) | = | 10780 | − | 98 | x | − | x | ( | 110 | − | x | ) |
97911 10 | − | 99 | x | − | x | × | 989 10 | + | x | x | = | 10780 | − | 98 | x | − | x | ( | 110 | − | x | ) |
97911 10 | − | 99 | x | − | x | × | 989 10 | + | x | x | = | 10780 | − | 98 | x | − | x | × | 110 | + | x | x |
97911 10 | − | 1979 10 | x | + | x | x | = | 10780 | − | 208 | x | + | x | x |
| x1= | 9889 101 |