( | 37 | − | 25 | − | x | ) | ( | 4 | + | 2 | x | ) | = | 90 |
方程左边 = | 37 | ( | 4 | + | 2 | x | ) | − | 25 | ( | 4 | + | 2 | x | ) | − | x | ( | 4 | + | 2 | x | ) |
= | 37 | × | 4 | + | 37 | × | 2 | x | − | 25 | ( | 4 | + | 2 | x | ) | − | x | ( | 4 | + | 2 | x | ) |
= | 148 | + | 74 | x | − | 25 | ( | 4 | + | 2 | x | ) | − | x | ( | 4 | + | 2 | x | ) |
= | 148 | + | 74 | x | − | 25 | × | 4 | − | 25 | × | 2 | x | − | x | ( | 4 | + | 2 | x | ) |
= | 148 | + | 74 | x | − | 100 | − | 50 | x | − | x | ( | 4 | + | 2 | x | ) |
= | 48 | + | 24 | x | − | x | ( | 4 | + | 2 | x | ) |
= | 48 | + | 24 | x | − | x | × | 4 | − | x | × | 2 | x |
= | 48 | + | 20 | x | − | x | × | 2 | x |
48 | + | 20 | x | − | x | × | 2 | x | = | 90 |