2 | × | 10 | ( | 20 | − | x | ) | = | 5 | × | 12 | x |
方程左边 = | 20 | ( | 20 | − | x | ) |
20 | ( | 20 | − | x | ) | = | 5 | × | 12 | x |
方程左边 = | 20 | × | 20 | − | 20 | x |
= | 400 | − | 20 | x |
400 | − | 20 | x | = | 5 | × | 12 | x |
方程右边 = | 60 | x |
400 | − | 20 | x | = | 60 | x |
- | 20 | x | − | 60 | x | = | - | 400 |
- | 80 | x | = | - | 400 |
400 | = | 80 | x |
80 | x | = | 400 |
x | = | 400 | ÷ | 80 |
= | 400 | × | 1 80 |
= | 5 | × | 1 |
x | = | 5 |