| ( | 20977 5 | + | 37 2 | y | ) | ÷ | ( | 100 | + | y | ) | = | 20 |
| 方程两边同时乘以: | ( | 100 | + | y | ) |
| ( | 20977 5 | + | 37 2 | y | ) | = | 20 | ( | 100 | + | y | ) |
20977 5 | + | 37 2 | y | = | 20 | ( | 100 | + | y | ) |
20977 5 | + | 37 2 | y | = | 20 | × | 100 | + | 20 | y |
20977 5 | + | 37 2 | y | = | 2000 | + | 20 | y |
37 2 | y | − | 20 | y | = | 2000 | − | 20977 5 |
| - | 3 2 | y | = | 2000 | − | 20977 5 |
| - | 3 2 | y | = | - | 10977 5 |
10977 5 | = | 3 2 | y |
3 2 | y | = | 10977 5 |
| y | = | 10977 5 | ÷ | 3 2 |
| = | 10977 5 | × | 2 3 |
| = | 3659 5 | × | 2 |
| y | = | 7318 5 |
| y | = | 1463.6 |