180 | ÷ | ( | 4 | + | x | ) | + | 180 | ÷ | ( | 4 | − | x | ) | = | 120 |
方程两边同时乘以: | ( | 4 | + | x | ) |
180 | + | 180 | ÷ | ( | 4 | − | x | ) | × | ( | 4 | + | x | ) | = | 120 | ( | 4 | + | x | ) |
180 | + | 180 | ÷ | ( | 4 | − | x | ) | × | 4 | + | 180 | ÷ | ( | 4 | − | x | ) | × | x | = | 120 | ( | 4 | + | x | ) |
180 | + | 180 | ÷ | ( | 4 | − | x | ) | × | 4 | + | 180 | ÷ | ( | 4 | − | x | ) | × | x | = | 120 | × | 4 | + | 120 | x |
180 | + | 720 | ÷ | ( | 4 | − | x | ) | + | 180 | ÷ | ( | 4 | − | x | ) | × | x | = | 480 | + | 120 | x |
方程两边同时乘以: | ( | 4 | − | x | ) |
180 | ( | 4 | − | x | ) | + | 720 | + | 180 | x | = | 480 | ( | 4 | − | x | ) | + | 120 | x | ( | 4 | − | x | ) |
180 | × | 4 | − | 180 | x | + | 720 | + | 180 | x | = | 480 | ( | 4 | − | x | ) | + | 120 | x | ( | 4 | − | x | ) |
180 | × | 4 | − | 180 | x | + | 720 | + | 180 | x | = | 480 | × | 4 | − | 480 | x | + | 120 | x | ( | 4 | − | x | ) |
720 | − | 180 | x | + | 720 | + | 180 | x | = | 1920 | − | 480 | x | + | 120 | x | ( | 4 | − | x | ) |
1440 | − | 0 | x | = | 1920 | − | 480 | x | + | 120 | x | ( | 4 | − | x | ) |
1440 | = | 1920 | − | 480 | x | + | 120 | x | × | 4 | − | 120 | x | x |
1440 | = | 1920 | − | 480 | x | + | 480 | x | − | 120 | x | x |
1440 | = | 1920 | − | 0 | x | − | 120 | x | x |