X | + | 400 | − | 2 | ÷ | 100 | × | ( | 20000 | + | X | ÷ | 13 100 | ) | = | 2200 |
方程左边 = | X | + | 400 | − | 1 50 | ( | 20000 | + | X | ÷ | 13 100 | ) |
X | + | 400 | − | 1 50 | ( | 20000 | + | X | ÷ | 13 100 | ) | = | 2200 |
方程左边 = | X | + | 400 | − | 1 50 | × | 20000 | − | 1 50 | X | ÷ | 13 100 |
= | X | + | 400 | − | 400 | − | 2 13 | X |
= | 11 13 | X | + | 0 |
11 13 | X | = | 2200 |
X | = | 2200 | ÷ | 11 13 |
= | 2200 | × | 13 11 |
= | 200 | × | 13 |
X | = | 2600 |