| ( | 2900 | − | 50 | x | ) | ( | 8 | + | 4 | x | ) | = | 5000 |
| Left side of the equation = | 2900 | ( | 8 | + | 4 | x | ) | − | 50 | x | ( | 8 | + | 4 | x | ) |
| = | 2900 | × | 8 | + | 2900 | × | 4 | x | − | 50 | x | ( | 8 | + | 4 | x | ) |
| = | 23200 | + | 11600 | x | − | 50 | x | ( | 8 | + | 4 | x | ) |
| = | 23200 | + | 11600 | x | − | 50 | x | × | 8 | − | 50 | x | × | 4 | x |
| = | 23200 | + | 11600 | x | − | 400 | x | − | 200 | x | x |
| = | 23200 | + | 11200 | x | − | 200 | x | x |
| 23200 | + | 11200 | x | − | 200 | x | x | = | 5000 |