200 | ( | 1 | + | 2 | × | a% | ) | × | 100 | + | 50 | ( | 1 | + | 6 | × | a% | ) | × | 160 | = | 0 |
方程左边 = | 20000 | ( | 1 | + | 2 | × | a% | ) | + | 8000 | ( | 1 | + | 6 | × | a% | ) |
20000 | ( | 1 | + | 2 | × | a% | ) | + | 8000 | ( | 1 | + | 6 | × | a% | ) | = | 0 |
方程左边 = | 20000 | × | 1 | + | 20000 | × | 2 | × | a% | + | 8000 | ( | 1 | + | 6 | × | a% | ) |
= | 20000 | + | 400 | a | + | 8000 | ( | 1 | + | 6 | × | a% | ) |
= | 20000 | + | 400 | a | + | 8000 | × | 1 | + | 8000 | × | 6 | × | a% |
= | 20000 | + | 400 | a | + | 8000 | + | 480 | a |
= | 28000 | + | 880 | a |
28000 | + | 880 | a | = | 0 |
880 | a | = | 0 | − | 28000 |
880 | a | = | - | 28000 |
a | = | - | 28000 | ÷ | 880 |
= | - | 28000 | × | 1 880 |
= | - | 350 | × | 1 11 |
a | = | - | 350 11 |
a | = | - 31.818182 |