200 | ( | X | − | 3 | ) | − | 150 | ( | X | + | 5 | ) | = | 0 |
方程左边 = | 200 | X | − | 200 | × | 3 | − | 150 | ( | X | + | 5 | ) |
= | 200 | X | − | 600 | − | 150 | ( | X | + | 5 | ) |
= | 200 | X | − | 600 | − | 150 | X | − | 150 | × | 5 |
= | 200 | X | − | 600 | − | 150 | X | − | 750 |
= | 50 | X | − | 1350 |
50 | X | − | 1350 | = | 0 |
50 | X | = | 0 | + | 1350 |
50 | X | = | 1350 |
X | = | 1350 | ÷ | 50 |
= | 1350 | × | 1 50 |
= | 27 | × | 1 |
X | = | 27 |