( | 90 | × | 3 10 | ) | − | x | = | 1 5 | ( | 90 | − | x | ) |
方程左边 = | 90 | × | 3 10 | − | x |
= | 27 | − | x |
27 | − | x | = | 1 5 | ( | 90 | − | x | ) |
方程右边 = | 1 5 | × | 90 | − | 1 5 | x |
= | 18 | − | 1 5 | x |
27 | − | x | = | 18 | − | 1 5 | x |
- | x | + | 1 5 | x | = | 18 | − | 27 |
- | 4 5 | x | = | 18 | − | 27 |
- | 4 5 | x | = | - | 9 |
9 | = | 4 5 | x |
4 5 | x | = | 9 |
x | = | 9 | ÷ | 4 5 |
= | 9 | × | 5 4 |
x | = | 45 4 |
x | = | 11.25 |