| 60 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 120 |
| 方程左边 = | 60 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 40 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 40 | + | x | × | 1 | ÷ | 3 |
| = | 40 | + | x | × | 1 3 |
| 40 | + | 1 3 | x | = | 120 |
1 3 | x | = | 120 | − | 40 |
1 3 | x | = | 80 |
| x | = | 80 | ÷ | 1 3 |
| = | 80 | × | 3 |
| x | = | 240 |
| 60 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 120 |
| 方程左边 = | 60 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 40 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 40 | + | x | × | 1 | ÷ | 3 |
| = | 40 | + | x | × | 1 3 |
| 40 | + | 1 3 | x | = | 120 |
1 3 | x | = | 120 | − | 40 |
1 3 | x | = | 80 |
| x | = | 80 | ÷ | 1 3 |
| = | 80 | × | 3 |
| x | = | 240 |
| 75 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 130 |
| 方程左边 = | 75 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 50 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 50 | + | x | × | 1 | ÷ | 3 |
| = | 50 | + | x | × | 1 3 |
| 50 | + | 1 3 | x | = | 130 |
1 3 | x | = | 130 | − | 50 |
1 3 | x | = | 80 |
| x | = | 80 | ÷ | 1 3 |
| = | 80 | × | 3 |
| x | = | 240 |
| 65 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 80 |
| 方程左边 = | 65 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 130 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 130 3 | + | x | × | 1 | ÷ | 3 |
| = | 130 3 | + | x | × | 1 3 |
130 3 | + | 1 3 | x | = | 80 |
1 3 | x | = | 80 | − | 130 3 |
1 3 | x | = | 110 3 |
| x | = | 110 3 | ÷ | 1 3 |
| = | 110 3 | × | 3 |
| = | 110 | × | 1 |
| x | = | 110 |
| 65 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 80 |
| 方程左边 = | 65 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 130 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 130 3 | + | x | × | 1 | ÷ | 3 |
| = | 130 3 | + | x | × | 1 3 |
130 3 | + | 1 3 | x | = | 80 |
1 3 | x | = | 80 | − | 130 3 |
1 3 | x | = | 110 3 |
| x | = | 110 3 | ÷ | 1 3 |
| = | 110 3 | × | 3 |
| = | 110 | × | 1 |
| x | = | 110 |
| 75 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 130 |
| 方程左边 = | 75 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 50 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 50 | + | x | × | 1 | ÷ | 3 |
| = | 50 | + | x | × | 1 3 |
| 50 | + | 1 3 | x | = | 130 |
1 3 | x | = | 130 | − | 50 |
1 3 | x | = | 80 |
| x | = | 80 | ÷ | 1 3 |
| = | 80 | × | 3 |
| x | = | 240 |
| 65 | ( | 2 | ÷ | 3 | ) | + | x | ( | 1 | ÷ | 3 | ) | = | 120 |
| 方程左边 = | 65 | × | 2 | ÷ | 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 130 3 | + | x | ( | 1 | ÷ | 3 | ) |
| = | 130 3 | + | x | × | 1 | ÷ | 3 |
| = | 130 3 | + | x | × | 1 3 |
130 3 | + | 1 3 | x | = | 120 |
1 3 | x | = | 120 | − | 130 3 |
1 3 | x | = | 230 3 |
| x | = | 230 3 | ÷ | 1 3 |
| = | 230 3 | × | 3 |
| = | 230 | × | 1 |
| x | = | 230 |