| ( | y | − | 1181 1000 | ) | ÷ | 4 5 | = | ( | 1177 1000 | − | y | ) | ÷ | 1 5 |
| 方程左边 = | y | × | 5 4 | − | 1181 1000 | × | 5 4 |
| = | y | × | 5 4 | − | 1181 800 |
5 4 | y | − | 1181 800 | = | ( | 1177 1000 | − | y | ) | ÷ | 1 5 |
| 方程右边 = | 1177 1000 | × | 5 | − | y | × | 5 |
| = | 1177 200 | − | y | × | 5 |
5 4 | y | − | 1181 800 | = | 1177 200 | − | 5 | y |
5 4 | y | + | 5 | y | = | 1177 200 | + | 1181 800 |
25 4 | y | = | 1177 200 | + | 1181 800 |
25 4 | y | = | 5889 800 |
| y | = | 5889 800 | ÷ | 25 4 |
| = | 5889 800 | × | 4 25 |
| = | 5889 200 | × | 1 25 |
| y | = | 5889 5000 |
| y | = | 1.1778 |