| ( | 25 | − | x | − | 15 | ) | ( | 200 | + | 15 | x | ) | = | 0 |
| Left side of the equation = | 25 | ( | 200 | + | 15 | x | ) | − | x | ( | 200 | + | 15 | x | ) | − | 15 | ( | 200 | + | 15 | x | ) |
| = | 25 | × | 200 | + | 25 | × | 15 | x | − | x | ( | 200 | + | 15 | x | ) | − | 15 | ( | 200 | + | 15 | x | ) |
| = | 5000 | + | 375 | x | − | x | ( | 200 | + | 15 | x | ) | − | 15 | ( | 200 | + | 15 | x | ) |
| = | 5000 | + | 375 | x | − | x | × | 200 | − | x | × | 15 | x | − | 15 | ( | 200 | + | 15 | x | ) |
| = | 5000 | + | 175 | x | − | x | × | 15 | x | − | 15 | ( | 200 | + | 15 | x | ) |
| = | 5000 | + | 175 | x | − | x | × | 15 | x | − | 15 | × | 200 | − | 15 | × | 15 | x |
| = | 5000 | + | 175 | x | − | x | × | 15 | x | − | 3000 | − | 225 | x |
| = | 2000 | − | 50 | x | − | x | × | 15 | x |
| 2000 | − | 50 | x | − | x | × | 15 | x | = | 0 |
| x1= | - | 40 3 |
| x2=10 |