| ( | 64 | − | 1 10 | x | ) | ( | 200 | + | x | ) | = | 14400 |
| Left side of the equation = | 64 | ( | 200 | + | x | ) | − | 1 10 | x | ( | 200 | + | x | ) |
| = | 64 | × | 200 | + | 64 | x | − | 1 10 | x | ( | 200 | + | x | ) |
| = | 12800 | + | 64 | x | − | 1 10 | x | ( | 200 | + | x | ) |
| = | 12800 | + | 64 | x | − | 1 10 | x | × | 200 | − | 1 10 | x | x |
| = | 12800 | + | 64 | x | − | 20 | x | − | 1 10 | x | x |
| = | 12800 | + | 44 | x | − | 1 10 | x | x |
| 12800 | + | 44 | x | − | 1 10 | x | x | = | 14400 |