57 | × | 100 | ÷ | X | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 78 |
方程两边同时乘以: | X |
57 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 78 | X |
- | 78 | X | = | - | 57 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 |
- | 78 | X | = | - | 380000 63 |
380000 63 | = | 78 | X |
78 | X | = | 380000 63 |
X | = | 380000 63 | ÷ | 78 |
= | 380000 63 | × | 1 78 |
= | 190000 63 | × | 1 39 |
X | = | 190000 2457 |
X | = | 77.330077 |