| ( | 35 | − | x | ) | ( | 100 | + | 4 | x | ) | = | 3596 |
| Left side of the equation = | 35 | ( | 100 | + | 4 | x | ) | − | x | ( | 100 | + | 4 | x | ) |
| = | 35 | × | 100 | + | 35 | × | 4 | x | − | x | ( | 100 | + | 4 | x | ) |
| = | 3500 | + | 140 | x | − | x | ( | 100 | + | 4 | x | ) |
| = | 3500 | + | 140 | x | − | x | × | 100 | − | x | × | 4 | x |
| = | 3500 | + | 40 | x | − | x | × | 4 | x |
| 3500 | + | 40 | x | − | x | × | 4 | x | = | 3596 |