| ( | 50 | + | 3 | x | ) | ( | 50 | + | 3 | x | ) | + | 16 | x | x | = | 7225 |
| 方程左边 = | 50 | ( | 50 | + | 3 | x | ) | + | 3 | x | ( | 50 | + | 3 | x | ) | + | 16 | x | x |
| = | 50 | × | 50 | + | 50 | × | 3 | x | + | 3 | x | ( | 50 | + | 3 | x | ) | + | 16 | x | x |
| = | 2500 | + | 150 | x | + | 3 | x | ( | 50 | + | 3 | x | ) | + | 16 | x | x |
| = | 2500 | + | 150 | x | + | 3 | x | × | 50 | + | 3 | x | × | 3 | x | + | 16 | x |
| = | 2500 | + | 150 | x | + | 150 | x | + | 9 | x | x | + | 16 | x | x |
| = | 2500 | + | 300 | x | + | 9 | x | x | + | 16 | x | x |
| 2500 | + | 300 | x | + | 9 | x | x | + | 16 | x | x | = | 7225 |