| 2400 | + | ( | 64 | − | n | ) | ( | 90 | + | 3 2 | n | ) | = | 8142 |
| 方程左边 = | 2400 | + | 64 | ( | 90 | + | 3 2 | n | ) | − | n | ( | 90 | + | 3 2 | n | ) |
| = | 2400 | + | 64 | × | 90 | + | 64 | × | 3 2 | n | − | n | ( | 90 | + | 3 2 | n | ) |
| = | 2400 | + | 5760 | + | 96 | n | − | n | ( | 90 | + | 3 2 | n | ) |
| = | 8160 | + | 96 | n | − | n | ( | 90 | + | 3 2 | n | ) |
| = | 8160 | + | 96 | n | − | n | × | 90 | − | n | × | 3 2 | n |
| = | 8160 | + | 6 | n | − | n | × | 3 2 | n |
| 8160 | + | 6 | n | − | n | × | 3 2 | n | = | 8142 |