1 4 | ( | 1 | + | 1 2 | x | ) | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) | = | 1 |
| 方程左边 = | 1 4 | × | 1 | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) | + | 1 4 | × | 1 2 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 1 4 | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) | + | 1 8 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 1 4 | × | 1 | + | 1 4 | × | 3 10 | ( | x | + | 9 10 | ) | + | 1 8 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 1 4 | + | 3 40 | ( | x | + | 9 10 | ) | + | 1 8 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 1 4 | + | 3 40 | x | + | 3 40 | × | 9 10 | + | 1 8 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 1 4 | + | 3 40 | x | + | 27 400 | + | 1 8 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 127 400 | + | 3 40 | x | + | 1 8 | x | ( | 1 | + | 3 10 | ( | x | + | 9 10 | ) | ) |
| = | 127 400 | + | 3 40 | x | + | 1 8 | x | × | 1 | + | 1 8 | x | × | 3 10 | ( | x | + | 9 10 | ) |
| = | 127 400 | + | 3 40 | x | + | 1 8 | x | + | 3 80 | x | ( | x | + | 9 10 | ) |
| = | 127 400 | + | 1 5 | x | + | 3 80 | x | ( | x | + | 9 10 | ) |
| = | 127 400 | + | 1 5 | x | + | 3 80 | x | x | + | 3 80 | x | × | 9 10 |
| = | 127 400 | + | 1 5 | x | + | 3 80 | x | x | + | 27 800 | x |
| = | 127 400 | + | 187 800 | x | + | 3 80 | x | x |
127 400 | + | 187 800 | x | + | 3 80 | x | x | = | 1 |
| x1= | - | 42 5 |
| x2= | 13 6 |