3 | ( | 45 2 | − | 3 2 | y | ) | − | 2 | y | = | 15 |
方程左边 = | 3 | × | 45 2 | − | 3 | × | 3 2 | y | − | 2 | y |
= | 135 2 | − | 9 2 | y | − | 2 | y |
= | 135 2 | − | 13 2 | y |
135 2 | − | 13 2 | y | = | 15 |
- | 13 2 | y | = | 15 | − | 135 2 |
- | 13 2 | y | = | - | 105 2 |
105 2 | = | 13 2 | y |
13 2 | y | = | 105 2 |
y | = | 105 2 | ÷ | 13 2 |
= | 105 2 | × | 2 13 |
= | 105 | × | 1 13 |
y | = | 105 13 |
y | = | 8.076923 |