( | 141 4 | − | 120 | x | ) | ( | 21 4 | − | 100 | x | ) | + | 441 16 | = | 0 |
方程左边 = | 141 4 | ( | 21 4 | − | 100 | x | ) | − | 120 | x | ( | 21 4 | − | 100 | x | ) | + | 441 16 |
= | 141 4 | × | 21 4 | − | 141 4 | × | 100 | x | − | 120 | x | ( | 21 4 | − | 100 | x | ) | + | 441 16 |
= | 2961 16 | − | 3525 | x | − | 120 | x | ( | 21 4 | − | 100 | x | ) | + | 441 16 |
= | 1701 8 | − | 3525 | x | − | 120 | x | ( | 21 4 | − | 100 | x | ) |
= | 1701 8 | − | 3525 | x | − | 120 | x | × | 21 4 | + | 120 | x | × | 100 | x |
= | 1701 8 | − | 3525 | x | − | 630 | x | + | 12000 | x | x |
= | 1701 8 | − | 4155 | x | + | 12000 | x | x |
1701 8 | − | 4155 | x | + | 12000 | x | x | = | 0 |