629 | − | 90 | x | + | 216 | = | 92 | − | 21 | x | − | 282 |
方程左边 = | 845 | − | 90 | x |
845 | − | 90 | x | = | 92 | − | 21 | x | − | 282 |
方程右边 = | - | 190 | − | 21 | x |
845 | − | 90 | x | = | - | 190 | − | 21 | x |
- | 90 | x | + | 21 | x | = | - | 190 | − | 845 |
- | 69 | x | = | - | 190 | − | 845 |
- | 69 | x | = | - | 1035 |
1035 | = | 69 | x |
69 | x | = | 1035 |
x | = | 1035 | ÷ | 69 |
= | 1035 | × | 1 69 |
= | 15 | × | 1 |
x | = | 15 |