99 100 | x | × | 10 | ÷ | ( | 10 | − | 1 4 | x | ) | − | 99 100 | x | − | 10 | × | 10 | ÷ | ( | 10 | − | 1 4 | x | ) | = | 70 |
| 方程两边同时乘以: | ( | 10 | − | 1 4 | x | ) |
99 100 | x | × | 10 | − | 99 100 | x | ( | 10 | − | 1 4 | x | ) | − | 10 | × | 10 | = | 70 | ( | 10 | − | 1 4 | x | ) |
99 100 | x | × | 10 | − | 99 100 | x | × | 10 | + | 99 100 | x | × | 1 4 | x | − | 10 | × | 10 | = | 70 | ( | 10 | − | 1 4 | x | ) |
99 100 | x | × | 10 | − | 99 100 | x | × | 10 | + | 99 100 | x | × | 1 4 | x | − | 10 | × | 10 | = | 70 | × | 10 | − | 70 | × | 1 4 | x |
99 10 | x | − | 99 10 | x | + | 99 400 | x | x | − | 100 | = | 700 | − | 35 2 | x |
| 0 | x | + | 99 400 | x | x | − | 100 | = | 700 | − | 35 2 | x |