| X | − | 12000 | ÷ | ( | 1000000 | ÷ | 3000 | ) | − | 15 | − | 300000 | ÷ | 100000 | − | 10 | − | X | × | 1 5 | = | 8 |
| 方程两边同时乘以: | ( | 1000000 | ÷ | 3000 | ) |
| X | ( | 1000000 | ÷ | 3000 | ) | − | 12000 | − | 15 | ( | 1000000 | ÷ | 3000 | ) | − | 300000 | ÷ | 100000 | × | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | = | 8 | ( | 1000000 | ÷ | 3000 | ) |
| X | × | 1000000 | ÷ | 3000 | − | 12000 | − | 15 | ( | 1000000 | ÷ | 3000 | ) | − | 300000 | ÷ | 100000 | × | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | = | 8 | ( | 1000000 | ÷ | 3000 | ) |
| X | × | 1000000 | ÷ | 3000 | − | 12000 | − | 15 | ( | 1000000 | ÷ | 3000 | ) | − | 300000 | ÷ | 100000 | × | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | = | 8 | × | 1000000 | ÷ | 3000 |
| X | × | 1000 3 | − | 12000 | − | 15 | ( | 1000000 | ÷ | 3000 | ) | − | 3 | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 12000 | − | 15 | × | 1000000 | ÷ | 3000 | − | 3 | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | = | 8000 3 |
1000 3 | X | − | 12000 | − | 5000 | − | 3 | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 17000 | − | 3 | ( | 1000000 | ÷ | 3000 | ) | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 17000 | − | 3 | × | 1000000 | ÷ | 3000 | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 17000 | − | 1000 | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 18000 | − | 10 | ( | 1000000 | ÷ | 3000 | ) | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 18000 | − | 10 | × | 1000000 | ÷ | 3000 | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 18000 | − | 10000 3 | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 64000 3 | − | X | × | 1 5 | ( | 1000000 | ÷ | 3000 | ) | = | 8000 3 |
1000 3 | X | − | 64000 3 | − | X | × | 1 5 | × | 1000000 | ÷ | 3000 | = | 8000 3 |
1000 3 | X | − | 64000 3 | − | X | × | 200 3 | = | 8000 3 |
800 3 | X | − | 64000 3 | = | 8000 3 |
800 3 | X | = | 8000 3 | + | 64000 3 |
800 3 | X | = | 24000 |
| X | = | 24000 | ÷ | 800 3 |
| = | 24000 | × | 3 800 |
| = | 30 | × | 3 |
| X | = | 90 |