| ( | 4 | − | 1 10 | x | ) | ( | 200000 | + | 1 5 | x | ) | = | 1200000 |
| Left side of the equation = | 4 | ( | 200000 | + | 1 5 | x | ) | − | 1 10 | x | ( | 200000 | + | 1 5 | x | ) |
| = | 4 | × | 200000 | + | 4 | × | 1 5 | x | − | 1 10 | x | ( | 200000 | + | 1 5 | x | ) |
| = | 800000 | + | 4 5 | x | − | 1 10 | x | ( | 200000 | + | 1 5 | x | ) |
| = | 800000 | + | 4 5 | x | − | 1 10 | x | × | 200000 | − | 1 10 | x | × | 1 5 | x |
| = | 800000 | + | 4 5 | x | − | 20000 | x | − | 1 50 | x | x |
| = | 800000 | − | 99996 5 | x | − | 1 50 | x | x |
| 800000 | − | 99996 5 | x | − | 1 50 | x | x | = | 1200000 |