1 4 | x | × | 1 4 | x | + | 1 4 | ( | 40 | − | x | ) | × | 1 4 | ( | 40 | − | x | ) | = | 58 |
| 方程左边 = | 1 16 | x | x | + | 1 16 | ( | 40 | − | x | ) | ( | 40 | − | x | ) |
1 16 | x | x | + | 1 16 | ( | 40 | − | x | ) | ( | 40 | − | x | ) | = | 58 |
| 方程左边 = | 1 16 | x | x | + | 1 16 | × | 40 | ( | 40 | − | x | ) | − | 1 16 | x | ( | 40 | − | x | ) |
| = | 1 16 | x | x | + | 5 2 | ( | 40 | − | x | ) | − | 1 16 | x | ( | 40 | − | x | ) |
| = | 1 16 | x | x | + | 5 2 | × | 40 | − | 5 2 | x | − | 1 16 | x | ( | 40 | − | x | ) |
| = | 1 16 | x | x | + | 100 | − | 5 2 | x | − | 1 16 | x | ( | 40 | − | x | ) |
| = | 1 16 | x | x | + | 100 | − | 5 2 | x | − | 1 16 | x | × | 40 | + | 1 16 | x | x |
| = | 1 16 | x | x | + | 100 | − | 5 2 | x | − | 5 2 | x | + | 1 16 | x | x |
| = | 1 16 | x | x | + | 100 | − | 5 | x | + | 1 16 | x | x |
1 16 | x | x | + | 100 | − | 5 | x | + | 1 16 | x | x | = | 58 |