1 4 | ( | 1 | + | 1 2 | x | ) | ( | 1 | + | 3 10 | x | ) | = | 1 |
| 方程左边 = | 1 4 | × | 1 | ( | 1 | + | 3 10 | x | ) | + | 1 4 | × | 1 2 | x | ( | 1 | + | 3 10 | x | ) |
| = | 1 4 | ( | 1 | + | 3 10 | x | ) | + | 1 8 | x | ( | 1 | + | 3 10 | x | ) |
| = | 1 4 | × | 1 | + | 1 4 | × | 3 10 | x | + | 1 8 | x | ( | 1 | + | 3 10 | x | ) |
| = | 1 4 | + | 3 40 | x | + | 1 8 | x | ( | 1 | + | 3 10 | x | ) |
| = | 1 4 | + | 3 40 | x | + | 1 8 | x | × | 1 | + | 1 8 | x | × | 3 10 | x |
| = | 1 4 | + | 3 40 | x | + | 1 8 | x | + | 3 80 | x | x |
| = | 1 4 | + | 1 5 | x | + | 3 80 | x | x |
1 4 | + | 1 5 | x | + | 3 80 | x | x | = | 1 |