| ( | 12 | + | x | ) | ( | 10 | x | + | 180 | ) | = | 2000 |
| Left side of the equation = | 12 | ( | 10 | x | + | 180 | ) | + | x | ( | 10 | x | + | 180 | ) |
| = | 12 | × | 10 | x | + | 12 | × | 180 | + | x | ( | 10 | x | + | 180 | ) |
| = | 120 | x | + | 2160 | + | x | ( | 10 | x | + | 180 | ) |
| = | 120 | x | + | 2160 | + | x | × | 10 | x | + | x | × | 180 |
| = | 300 | x | + | 2160 | + | x | × | 10 | x |
| 300 | x | + | 2160 | + | x | × | 10 | x | = | 2000 |