| ( | 35 | + | 3 | a | ÷ | 4 | ) | ( | 1600 | − | 32 | a | ) | + | 400 | ( | 70 | + | a | ) | = | 21000 | + | 10500 |
| 方程左边 = | 35 | ( | 1600 | − | 32 | a | ) | + | 3 | a | ÷ | 4 | × | ( | 1600 | − | 32 | a | ) | + | 400 | ( | 70 | + | a | ) |
| = | 35 | ( | 1600 | − | 32 | a | ) | + | 3 4 | a | ( | 1600 | − | 32 | a | ) | + | 400 | ( | 70 | + | a | ) |
| = | 35 | × | 1600 | − | 35 | × | 32 | a | + | 3 4 | a | ( | 1600 | − | 32 | a | ) | + | 400 | ( | 70 | + | a | ) |
| = | 56000 | − | 1120 | a | + | 3 4 | a | ( | 1600 | − | 32 | a | ) | + | 400 | ( | 70 | + | a | ) |
| = | 56000 | − | 1120 | a | + | 3 4 | a | × | 1600 | − | 3 4 | a | × | 32 | a | + | 400 | ( | 70 | + | a | ) |
| = | 56000 | − | 1120 | a | + | 1200 | a | − | 24 | a | a | + | 400 | ( | 70 | + | a | ) |
| = | 56000 | + | 80 | a | − | 24 | a | a | + | 400 | ( | 70 | + | a | ) |
| = | 56000 | + | 80 | a | − | 24 | a | a | + | 400 | × | 70 | + | 400 | a |
| = | 56000 | + | 80 | a | − | 24 | a | a | + | 28000 | + | 400 | a |
| = | 84000 | + | 480 | a | − | 24 | a | a |
| 84000 | + | 480 | a | − | 24 | a | a | = | 21000 | + | 10500 |
| 方程右边 = | 31500 |
| 84000 | + | 480 | a | − | 24 | a | a | = | 31500 |