| 60 | ( | 1 | − | x | ) | × | 80 | ( | 1 | + | 2 | x | ) | = | ( | 1600 | × | 16 | − | 7120 | ) | ÷ | 15 | + | 36 | × | 80 | ( | 1 | + | 2 | x | ) |
| 方程左边 = | 4800 | ( | 1 | − | x | ) | ( | 1 | + | 2 | x | ) |
| 4800 | ( | 1 | − | x | ) | ( | 1 | + | 2 | x | ) | = | ( | 1600 | × | 16 | − | 7120 | ) | ÷ | 15 | + | 36 | × | 80 | ( | 1 | + | 2 | x | ) |
| 方程左边 = | 4800 | × | 1 | ( | 1 | + | 2 | x | ) | − | 4800 | x | ( | 1 | + | 2 | x | ) |
| = | 4800 | ( | 1 | + | 2 | x | ) | − | 4800 | x | ( | 1 | + | 2 | x | ) |
| = | 4800 | × | 1 | + | 4800 | × | 2 | x | − | 4800 | x | ( | 1 | + | 2 | x | ) |
| = | 4800 | + | 9600 | x | − | 4800 | x | ( | 1 | + | 2 | x | ) |
| = | 4800 | + | 9600 | x | − | 4800 | x | × | 1 | − | 4800 | x | × | 2 | x |
| = | 4800 | + | 9600 | x | − | 4800 | x | − | 9600 | x | x |
| = | 4800 | + | 4800 | x | − | 9600 | x | x |
| 4800 | + | 4800 | x | − | 9600 | x | x | = | ( | 1600 | × | 16 | − | 7120 | ) | ÷ | 15 | + | 36 | × | 80 | ( | 1 | + | 2 | x | ) |
| 方程右边 = | ( | 1600 | × | 16 | − | 7120 | ) | × | 1 15 | + | 2880 | ( | 1 | + | 2 | x | ) |
| 4800 | + | 4800 | x | − | 9600 | x | x | = | ( | 1600 | × | 16 | − | 7120 | ) | × | 1 15 | + | 2880 | ( | 1 | + | 2 | x | ) |
| 方程右边 = | 1600 | × | 16 | × | 1 15 | − | 7120 | × | 1 15 | + | 2880 | ( | 1 | + | 2 | x | ) |
| = | 5120 3 | − | 1424 3 | + | 2880 | ( | 1 | + | 2 | x | ) |
| = | 1232 | + | 2880 | ( | 1 | + | 2 | x | ) |
| = | 1232 | + | 2880 | × | 1 | + | 2880 | × | 2 | x |
| = | 1232 | + | 2880 | + | 5760 | x |
| = | 4112 | + | 5760 | x |
| 4800 | + | 4800 | x | − | 9600 | x | x | = | 4112 | + | 5760 | x |