1 2 | × | 40 | + | ( | X | − | 1 | ÷ | 3 | ) | × | 40 | + | 30 | X | = | 170 |
方程左边 = | 20 | + | ( | X | − | 1 | ÷ | 3 | ) | × | 40 | + | 30 | X |
20 | + | ( | X | − | 1 | ÷ | 3 | ) | × | 40 | + | 30 | X | = | 170 |
方程左边 = | 20 | + | X | × | 40 | − | 1 | ÷ | 3 | × | 40 | + | 30 | X |
= | 20 | + | X | × | 40 | − | 40 3 | + | 30 | X |
= | 20 3 | + | 70 | X |
20 3 | + | 70 | X | = | 170 |
70 | X | = | 170 | − | 20 3 |
70 | X | = | 490 3 |
X | = | 490 3 | ÷ | 70 |
= | 490 3 | × | 1 70 |
= | 7 3 | × | 1 |
X | = | 7 3 |
X | = | 2.333333 |