40 | x | + | 80 | x | − | 480 | = | 120 |
方程左边 = | 120 | x | − | 480 |
120 | x | − | 480 | = | 120 |
120 | x | = | 120 | + | 480 |
120 | x | = | 600 |
x | = | 600 | ÷ | 120 |
= | 600 | × | 1 120 |
= | 5 | × | 1 |
x | = | 5 |
- | 80 | x | + | 480 | − | 40 | x | = | 120 |
方程左边 = | - | 120 | x | + | 480 |
- | 120 | x | + | 480 | = | 120 |
- | 120 | x | = | 120 | − | 480 |
- | 120 | x | = | - | 360 |
360 | = | 120 | x |
120 | x | = | 360 |
x | = | 360 | ÷ | 120 |
= | 360 | × | 1 120 |
= | 3 | × | 1 |
x | = | 3 |