w | w | ( | 1 | + | 1 5 | w | × | 1 5 | w | ) | ( | 1 | + | 1 20 | w | × | 1 20 | w | ) | = | 36 |
方程左边 = | w | w | × | 1 | ( | 1 | + | 1 20 | w | × | 1 20 | w | ) | + | w | w | × | 1 5 | w | × | 1 5 | w | ( | 1 | + | 1 20 | w | × | 1 20 | w | ) |
= | w | w | × | 1 | ( | 1 | + | 1 20 | w | × | 1 20 | w | ) | + | w | w | × | 1 25 | w | w | ( | 1 | + | 1 20 | w | × | 1 20 | w | ) |
= | w | w | × | 1 | × | 1 | + | w | w | × | 1 | × | 1 20 | w | × | 1 20 | w | + | w |
= | w | w | × | 1 | + | w | w | × | 1 400 | w | w | + | w | w | × | 1 25 | w |
= | w | w | × | 1 | + | w | w | × | 1 400 | w | w | + | w | w | × | 1 25 | w |
= | w | w | × | 1 | + | w | w | × | 1 400 | w | w | + | w | w | × | 1 25 | w |
w | w | × | 1 | + | w | w | × | 1 400 | w | w | + | w | w | × | 1 25 | w | = | 36 |