20 | × | 2 | + | 5 2 | ( | x | − | 20 | ) | + | 3 10 | x | = | 74 |
方程左边 = | 40 | + | 5 2 | ( | x | − | 20 | ) | + | 3 10 | x |
40 | + | 5 2 | ( | x | − | 20 | ) | + | 3 10 | x | = | 74 |
方程左边 = | 40 | + | 5 2 | x | − | 5 2 | × | 20 | + | 3 10 | x |
= | 40 | + | 5 2 | x | − | 50 | + | 3 10 | x |
= | - | 10 | + | 14 5 | x |
- | 10 | + | 14 5 | x | = | 74 |
14 5 | x | = | 74 | + | 10 |
14 5 | x | = | 84 |
x | = | 84 | ÷ | 14 5 |
= | 84 | × | 5 14 |
= | 6 | × | 5 |
x | = | 30 |