( | 300 | - | x | ) | × | 3 | ÷ | 10 | = | ( | 400 | - | x | ) | × | 2 | ÷ | 10 |
方程左边 = | ( | 300 | - | x | ) | × | 3 10 |
( | 300 | - | x | ) | × | 3 10 | = | ( | 400 | - | x | ) | × | 2 | ÷ | 10 |
方程左边 = | 300 | × | 3 10 | - | x | × | 3 10 |
= | 90 | - | x | × | 3 10 |
90 | - | 3 10 | x | = | ( | 400 | - | x | ) | × | 2 | ÷ | 10 |
方程右边 = | ( | 400 | - | x | ) | × | 1 5 |
90 | - | 3 10 | x | = | ( | 400 | - | x | ) | × | 1 5 |
方程右边 = | 400 | × | 1 5 | - | x | × | 1 5 |
= | 80 | - | x | × | 1 5 |
90 | - | 3 10 | x | = | 80 | - | 1 5 | x |
- | 3 10 | x | + | 1 5 | x | = | 80 | - | 90 |
- | 1 10 | x | = | 80 | - | 90 |
- | 1 10 | x | = | - | 10 |
1 10 | x | = | 10 |
x | = | 10 | ÷ | 1 10 |
= | 10 | × | 10 |
x | = | 100 |