3 | + | ( | y | + | 1 | ) | − | 2 | ( | y | − | 1 | ) | = | 3 | y | − | 4 |
方程左边 = | 3 | + | y | + | 1 | − | 2 | ( | y | − | 1 | ) |
= | 4 | + | y | − | 2 | ( | y | − | 1 | ) |
= | 4 | + | y | − | 2 | y | + | 2 | × | 1 |
= | 4 | + | y | − | 2 | y | + | 2 |
= | 6 | − | 1 | y |
6 | − | 1 | y | = | 3 | y | − | 4 |
- | 1 | y | − | 3 | y | = | - | 4 | − | 6 |
- | 4 | y | = | - | 4 | − | 6 |
- | 4 | y | = | - | 10 |
10 | = | 4 | y |
4 | y | = | 10 |
y | = | 10 | ÷ | 4 |
= | 10 | × | 1 4 |
= | 5 | × | 1 2 |
y | = | 5 2 |
y | = | 2.5 |