( | P | − | 10 | ) | ( | 160 | − | P | ) | + | ( | P | − | 10 | ) | ( | 65 | − | 1 2 | P | ) | = | 0 |
方程左边 = | P | ( | 160 | − | P | ) | − | 10 | ( | 160 | − | P | ) | + | ( | P | − | 10 | ) | ( | 65 | − | 1 2 | P | ) |
= | P | × | 160 | − | P | P | − | 10 | ( | 160 | − | P | ) | + | ( | P | − | 10 | ) | ( | 65 | − | 1 2 | P | ) |
= | 160 | P | − | P | P | − | 10 | × | 160 | + | 10 | P | + | ( | P | − | 10 | ) | ( | 65 | − | 1 2 | P | ) |
= | 160 | P | − | P | P | − | 1600 | + | 10 | P | + | ( | P | − | 10 | ) | ( | 65 | − | 1 2 | P | ) |
= | 170 | P | − | P | P | − | 1600 | + | ( | P | − | 10 | ) | ( | 65 | − | 1 2 | P | ) |
= | 170 | P | − | P | P | − | 1600 | + | P | ( | 65 | − | 1 2 | P | ) | − | 10 | ( | 65 | − | 1 2 | P | ) |
= | 170 | P | − | P | P | − | 1600 | + | P | × | 65 | − | P | × | 1 2 | P | − | 10 | ( | 65 | − | 1 2 | P | ) |
= | 235 | P | − | P | P | − | 1600 | − | P | × | 1 2 | P | − | 10 | ( | 65 | − | 1 2 | P | ) |
= | 235 | P | − | P | P | − | 1600 | − | P | × | 1 2 | P | − | 10 | × | 65 | + | 10 | × | 1 2 |
= | 235 | P | − | P | P | − | 1600 | − | P | × | 1 2 | P | − | 650 | + | 5 | P |
= | 240 | P | − | P | P | − | 2250 | − | P | × | 1 2 | P |
240 | P | − | P | P | − | 2250 | − | P | × | 1 2 | P | = | 0 |