| ( | 700 | x | + | 600 | ) | × | 3 | × | 25 | ÷ | 7 4 | = | 150000 |
| 方程左边 = | ( | 700 | x | + | 600 | ) | × | 300 7 |
| ( | 700 | x | + | 600 | ) | × | 300 7 | = | 150000 |
| 方程左边 = | 700 | x | × | 300 7 | + | 600 | × | 300 7 |
| = | 30000 | x | + | 180000 7 |
| 30000 | x | + | 180000 7 | = | 150000 |
| 30000 | x | = | 150000 | − | 180000 7 |
| 30000 | x | = | 870000 7 |
| x | = | 870000 7 | ÷ | 30000 |
| = | 870000 7 | × | 1 30000 |
| = | 29 7 | × | 1 |
| x | = | 29 7 |
| x | = | 4.142857 |