81 | × | 100 | ÷ | x | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 129 |
方程两边同时乘以: | x |
81 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 129 | x |
- | 129 | x | = | - | 81 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 |
- | 129 | x | = | - | 60000 7 |
60000 7 | = | 129 | x |
129 | x | = | 60000 7 |
x | = | 60000 7 | ÷ | 129 |
= | 60000 7 | × | 1 129 |
= | 20000 7 | × | 1 43 |
x | = | 20000 301 |
x | = | 66.445183 |