| 75 | ÷ | ( | x | + | 4 | ) | + | 1 | ÷ | 2 | + | 126 | ÷ | ( | x | − | 4 | ) | = | 5 |
| 方程两边同时乘以: | ( | x | + | 4 | ) |
| 75 | + | 1 | ÷ | 2 | × | ( | x | + | 4 | ) | + | 126 | ÷ | ( | x | − | 4 | ) | × | ( | x | + | 4 | ) | = | 5 | ( | x | + | 4 | ) |
| 75 | + | 1 | ÷ | 2 | × | x | + | 1 | ÷ | 2 | × | 4 | + | 126 | ÷ | ( | x | − | 4 | ) | × | ( | x | + | 4 | ) | = | 5 | ( | x | + | 4 | ) |
| 75 | + | 1 | ÷ | 2 | × | x | + | 1 | ÷ | 2 | × | 4 | + | 126 | ÷ | ( | x | − | 4 | ) | × | ( | x | + | 4 | ) | = | 5 | x | + | 5 | × | 4 |
| 75 | + | 1 2 | x | + | 2 | + | 126 | ÷ | ( | x | − | 4 | ) | × | ( | x | + | 4 | ) | = | 5 | x | + | 20 |
| 77 | + | 1 2 | x | + | 126 | ÷ | ( | x | − | 4 | ) | × | ( | x | + | 4 | ) | = | 5 | x | + | 20 |
| 方程两边同时乘以: | ( | x | − | 4 | ) |
| 77 | ( | x | − | 4 | ) | + | 1 2 | x | ( | x | − | 4 | ) | + | 126 | ( | x | + | 4 | ) | = | 5 | x | ( | x | − | 4 | ) | + | 20 | ( | x | − | 4 | ) |
| 77 | x | − | 77 | × | 4 | + | 1 2 | x | ( | x | − | 4 | ) | + | 126 | ( | x | + | 4 | ) | = | 5 | x | ( | x | − | 4 | ) | + | 20 | ( | x | − | 4 | ) |
| 77 | x | − | 77 | × | 4 | + | 1 2 | x | ( | x | − | 4 | ) | + | 126 | ( | x | + | 4 | ) | = | 5 | x | x | − | 5 | x | × | 4 | + | 20 | ( | x | − | 4 | ) |
| 77 | x | − | 308 | + | 1 2 | x | ( | x | − | 4 | ) | + | 126 | ( | x | + | 4 | ) | = | 5 | x | x | − | 20 | x | + | 20 | ( | x | − | 4 | ) |
| 77 | x | − | 308 | + | 1 2 | x | x | − | 1 2 | x | × | 4 | + | 126 | ( | x | + | 4 | ) | = | 5 | x | x | − | 20 | x | + | 20 | ( | x | − | 4 | ) |
| 77 | x | − | 308 | + | 1 2 | x | x | − | 1 2 | x | × | 4 | + | 126 | ( | x | + | 4 | ) | = | 5 | x | x | − | 20 | x | + | 20 | x | − | 20 | × | 4 |
| 77 | x | − | 308 | + | 1 2 | x | x | − | 2 | x | + | 126 | ( | x | + | 4 | ) | = | 5 | x | x | − | 20 | x | + | 20 | x | − | 80 |
| 75 | x | − | 308 | + | 1 2 | x | x | + | 126 | ( | x | + | 4 | ) | = | 5 | x | x | − | 0 | x | − | 80 |
| 75 | x | − | 308 | + | 1 2 | x | x | + | 126 | x | + | 126 | × | 4 | = | 5 | x | x | − | 80 |
| 75 | x | − | 308 | + | 1 2 | x | x | + | 126 | x | + | 504 | = | 5 | x | x | − | 80 |
| 201 | x | + | 196 | + | 1 2 | x | x | = | 5 | x | x | − | 80 |
| x1= | - | 4 3 |
| x2=46 |