| x | ( | x | + | 1 | ) | ( | x | + | 10 | ) | = | - | 470 |
| Left side of the equation = | x | x | ( | x | + | 10 | ) | + | x | × | 1 | ( | x | + | 10 | ) |
| = | x | x | x | + | x | x | × | 10 | + | x | × | 1 | ( | x | + | 10 | ) |
| = | x | x | x | + | x | x | × | 10 | + | x | × | 1 | x | + | x | × | 1 | × | 10 |
| = | x | x | x | + | x | x | × | 10 | + | x | × | 1 | x | + | x | × | 10 |
| x | x | x | + | x | x | × | 10 | + | x | × | 1 | x | + | 10 | x | = | - | 470 |