P | × | 20000 | − | 400000 | = | ( | P | − | 700 | ) | × | 20000 | − | 3000000 |
方程右边 = | P | × | 20000 | − | 700 | × | 20000 | − | 3000000 |
= | P | × | 20000 | − | 14000000 | − | 3000000 |
= | 20000 | P | − | 17000000 |
20000 | P | − | 400000 | = | 20000 | P | − | 17000000 |
20000 | P | − | 20000 | P | = | - | 17000000 | + | 400000 |
0 | P | = | - | 17000000 | + | 400000 |
0 | P | = | - | 16600000 |