100 | × | 291 10 | + | x | × | 20 | = | ( | 100 | + | x | ) | × | 25 |
方程左边 = | 2910 | + | x | × | 20 |
2910 | + | 20 | x | = | ( | 100 | + | x | ) | × | 25 |
方程右边 = | 100 | × | 25 | + | x | × | 25 |
= | 2500 | + | x | × | 25 |
2910 | + | 20 | x | = | 2500 | + | 25 | x |
20 | x | − | 25 | x | = | 2500 | − | 2910 |
- | 5 | x | = | 2500 | − | 2910 |
- | 5 | x | = | - | 410 |
410 | = | 5 | x |
5 | x | = | 410 |
x | = | 410 | ÷ | 5 |
= | 410 | × | 1 5 |
= | 82 | × | 1 |
x | = | 82 |