( | 1100 | − | 750 | − | x | ) | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) | = | 12000 |
方程左边 = | 1100 | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) | − | 750 | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) | − | x | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) |
= | 1100 | × | 30 | + | 1100 | x | ÷ | 50 | × | x | × | 10 | − | 750 | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) | − | x | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) |
= | 33000 | + | 220 | x | x | − | 750 | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) | − | x | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) |
= | 33000 | + | 220 | x | x | − | 750 | × | 30 | − | 750 | x | ÷ | 50 | × | x | × | 10 | − | x |
= | 33000 | + | 220 | x | x | − | 22500 | − | 150 | x | x | − | x | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) |
= | 10500 | + | 220 | x | x | − | 150 | x | x | − | x | ( | 30 | + | x | ÷ | 50 | × | x | × | 10 | ) |
= | 10500 | + | 220 | x | x | − | 150 | x | x | − | x | × | 30 | − | x | x | ÷ | 50 |
= | 10500 | + | 220 | x | x | − | 150 | x | x | − | x | × | 30 | − | x | x | × | 1 5 |
10500 | + | 220 | x | x | − | 150 | x | x | − | 30 | x | − | x | x | × | 1 5 | = | 12000 |