( | 40 | − | 4 | X | ) | ( | 25 | − | 2 | X | ) | = | 3 | × | 200 |
方程左边 = | 40 | ( | 25 | − | 2 | X | ) | − | 4 | X | ( | 25 | − | 2 | X | ) |
= | 40 | × | 25 | − | 40 | × | 2 | X | − | 4 | X | ( | 25 | − | 2 | X | ) |
= | 1000 | − | 80 | X | − | 4 | X | ( | 25 | − | 2 | X | ) |
= | 1000 | − | 80 | X | − | 4 | X | × | 25 | + | 4 | X | × | 2 | X |
= | 1000 | − | 80 | X | − | 100 | X | + | 8 | X | X |
= | 1000 | − | 180 | X | + | 8 | X | X |
1000 | − | 180 | X | + | 8 | X | X | = | 3 | × | 200 |
方程右边 = | 600 |
1000 | − | 180 | X | + | 8 | X | X | = | 600 |
X1= | 5 2 |
X2=20 |