( | x | − | 25 | ) | × | 3 | ÷ | 7 | = | ( | x | − | 25 | − | 42 | ) | × | 5 | ÷ | 7 |
方程左边 = | ( | x | − | 25 | ) | × | 3 7 |
( | x | − | 25 | ) | × | 3 7 | = | ( | x | − | 25 | − | 42 | ) | × | 5 | ÷ | 7 |
方程左边 = | x | × | 3 7 | − | 25 | × | 3 7 |
= | x | × | 3 7 | − | 75 7 |
3 7 | x | − | 75 7 | = | ( | x | − | 25 | − | 42 | ) | × | 5 | ÷ | 7 |
方程右边 = | ( | x | − | 25 | − | 42 | ) | × | 5 7 |
3 7 | x | − | 75 7 | = | ( | x | − | 25 | − | 42 | ) | × | 5 7 |
方程右边 = | x | × | 5 7 | − | 25 | × | 5 7 | − | 42 | × | 5 7 |
= | x | × | 5 7 | − | 125 7 | − | 30 |
= | 5 7 | x | − | 335 7 |
3 7 | x | − | 75 7 | = | 5 7 | x | − | 335 7 |
3 7 | x | − | 5 7 | x | = | - | 335 7 | + | 75 7 |
- | 2 7 | x | = | - | 335 7 | + | 75 7 |
- | 2 7 | x | = | - | 260 7 |
260 7 | = | 2 7 | x |
2 7 | x | = | 260 7 |
x | = | 260 7 | ÷ | 2 7 |
= | 260 7 | × | 7 2 |
= | 130 | × | 1 |
x | = | 130 |