| ( | 4 | x | + | 3 | ) | ÷ | 5 | = | ( | 2 | x | + | 15 | ) | ÷ | 7 |
| 方程左边 = | 4 | x | × | 1 5 | + | 3 | × | 1 5 |
| = | 4 5 | x | + | 3 5 |
4 5 | x | + | 3 5 | = | ( | 2 | x | + | 15 | ) | ÷ | 7 |
| 方程右边 = | 2 | x | × | 1 7 | + | 15 | × | 1 7 |
| = | 2 7 | x | + | 15 7 |
4 5 | x | + | 3 5 | = | 2 7 | x | + | 15 7 |
4 5 | x | − | 2 7 | x | = | 15 7 | − | 3 5 |
18 35 | x | = | 15 7 | − | 3 5 |
18 35 | x | = | 54 35 |
| x | = | 54 35 | ÷ | 18 35 |
| = | 54 35 | × | 35 18 |
| = | 3 | × | 1 |
| x | = | 3 |