20 | ÷ | ( | x | − | 20 | ) | = | ( | x | − | 20 | ) | ÷ | 98 |
方程两边同时乘以: | ( | x | − | 20 | ) |
20 | = | ( | x | − | 20 | ) | ÷ | 98 | × | ( | x | − | 20 | ) |
20 | = | x | ÷ | 98 | × | ( | x | − | 20 | ) | − | 20 | ÷ | 98 | × | ( | x | − | 20 | ) |
20 | = | x | × | 1 98 | ( | x | − | 20 | ) | − | 10 49 | ( | x | − | 20 | ) |
20 | = | x | × | 1 98 | x | − | x | × | 1 98 | × | 20 | − | 10 49 | ( | x | − | 20 | ) |
20 | = | x | × | 1 98 | x | − | x | × | 10 49 | − | 10 49 | ( | x | − | 20 | ) |
20 | = | x | × | 1 98 | x | − | 10 49 | x | − | 10 49 | x | + | 10 49 | × | 20 |
20 | = | x | × | 1 98 | x | − | 10 49 | x | − | 10 49 | x | + | 200 49 |
20 | = | x | × | 1 98 | x | − | 20 49 | x | + | 200 49 |