| 240 | = | 240 | ( | 1 10 | + | 3 5 | + | 3 50 | ) | ( | 1 | + | a% | ) |
| 方程右边 = | 240 | × | 1 10 | ( | 1 | + | a% | ) | + | 240 | × | 3 5 | ( | 1 | + | a% | ) | + | 240 | × | 3 50 | ( | 1 | + | a% | ) |
| = | 24 | ( | 1 | + | a% | ) | + | 144 | ( | 1 | + | a% | ) | + | 72 5 | ( | 1 | + | a% | ) |
| = | 24 | × | 1 | + | 24 | × | a% | + | 144 | ( | 1 | + | a% | ) | + | 72 5 | ( | 1 | + | a% | ) |
| = | 24 | + | 6 25 | a | + | 144 | ( | 1 | + | a% | ) | + | 72 5 | ( | 1 | + | a% | ) |
| = | 24 | + | 6 25 | a | + | 144 | × | 1 | + | 144 | × | a% | + | 72 5 | ( | 1 | + | a% | ) |
| = | 24 | + | 6 25 | a | + | 144 | + | 36 25 | a | + | 72 5 | ( | 1 | + | a% | ) |
| = | 168 | + | 42 25 | a | + | 72 5 | ( | 1 | + | a% | ) |
| = | 168 | + | 42 25 | a | + | 72 5 | × | 1 | + | 72 5 | × | a% |
| = | 168 | + | 42 25 | a | + | 72 5 | + | 18 125 | a |
| = | 912 5 | + | 228 125 | a |
| 240 | = | 912 5 | + | 228 125 | a |
| - | 228 125 | a | = | 912 5 | − | 240 |
| - | 228 125 | a | = | - | 288 5 |
288 5 | = | 228 125 | a |
228 125 | a | = | 288 5 |
| a | = | 288 5 | ÷ | 228 125 |
| = | 288 5 | × | 125 228 |
| = | 24 | × | 25 19 |
| a | = | 600 19 |
| a | = | 31.578947 |