( | 15 | − | 2 | X | ) | ( | 8 | − | 2 | X | ) | = | 15 | × | 8 | ÷ | 2 |
方程左边 = | 15 | ( | 8 | − | 2 | X | ) | − | 2 | X | ( | 8 | − | 2 | X | ) |
= | 15 | × | 8 | − | 15 | × | 2 | X | − | 2 | X | ( | 8 | − | 2 | X | ) |
= | 120 | − | 30 | X | − | 2 | X | ( | 8 | − | 2 | X | ) |
= | 120 | − | 30 | X | − | 2 | X | × | 8 | + | 2 | X | × | 2 | X |
= | 120 | − | 30 | X | − | 16 | X | + | 4 | X | X |
= | 120 | − | 46 | X | + | 4 | X | X |
120 | − | 46 | X | + | 4 | X | X | = | 15 | × | 8 | ÷ | 2 |
方程右边 = | 60 |
120 | − | 46 | X | + | 4 | X | X | = | 60 |
X1= | 3 2 |
X2=10 |