150 | x | ( | 29 | − | 22 | ) | + | 90 | x | × | 30 | x | ( | 40 | x | − | 30 | ) | = | 1950 | + | 720 |
方程左边 = | 150 | x | ( | 29 | − | 22 | ) | + | 2700 | x | x | ( | 40 | x | − | 30 | ) |
150 | x | ( | 29 | − | 22 | ) | + | 2700 | x | x | ( | 40 | x | − | 30 | ) | = | 1950 | + | 720 |
方程左边 = | 150 | x | × | 29 | − | 150 | x | × | 22 | + | 2700 | x | x | ( | 40 | x | − | 30 | ) |
= | 4350 | x | − | 3300 | x | + | 2700 | x | x | ( | 40 | x | − | 30 | ) |
= | 1050 | x | + | 2700 | x | x | ( | 40 | x | − | 30 | ) |
= | 1050 | x | + | 2700 | x | x | × | 40 | x | − | 2700 | x | x | × | 30 |
= | 1050 | x | + | 108000 | x | x | x | − | 81000 | x | x |
1050 | x | + | 108000 | x | x | x | − | 81000 | x | x | = | 1950 | + | 720 |
方程右边 = | 2670 |
1050 | x | + | 108000 | x | x | x | − | 81000 | x | x | = | 2670 |