| ( | 200 | − | 144 | − | 2 | x | ) | ( | 120 | + | 6 | x | ) | = | 0 |
| Left side of the equation = | 200 | ( | 120 | + | 6 | x | ) | − | 144 | ( | 120 | + | 6 | x | ) | − | 2 | x | ( | 120 | + | 6 | x | ) |
| = | 200 | × | 120 | + | 200 | × | 6 | x | − | 144 | ( | 120 | + | 6 | x | ) | − | 2 | x | ( | 120 | + | 6 | x | ) |
| = | 24000 | + | 1200 | x | − | 144 | ( | 120 | + | 6 | x | ) | − | 2 | x | ( | 120 | + | 6 | x | ) |
| = | 24000 | + | 1200 | x | − | 144 | × | 120 | − | 144 | × | 6 | x | − | 2 | x | ( | 120 | + | 6 | x | ) |
| = | 24000 | + | 1200 | x | − | 17280 | − | 864 | x | − | 2 | x | ( | 120 | + | 6 | x | ) |
| = | 6720 | + | 336 | x | − | 2 | x | ( | 120 | + | 6 | x | ) |
| = | 6720 | + | 336 | x | − | 2 | x | × | 120 | − | 2 | x | × | 6 | x |
| = | 6720 | + | 336 | x | − | 240 | x | − | 12 | x | x |
| = | 6720 | + | 96 | x | − | 12 | x | x |
| 6720 | + | 96 | x | − | 12 | x | x | = | 0 |