| 105 | ( | x | − | 10 | ) | − | 5 | ( | 11 | + | x | ) | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) | = | 0 |
| Left side of the equation = | 105 | x | − | 105 | × | 10 | − | 5 | ( | 11 | + | x | ) | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) |
| = | 105 | x | − | 1050 | − | 5 | ( | 11 | + | x | ) | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) |
| = | 105 | x | − | 1050 | − | 5 | × | 11 | ( | x | − | 10 | ) | − | 5 | x | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 |
| = | 105 | x | − | 1050 | − | 55 | ( | x | − | 10 | ) | − | 5 | x | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) |
| = | 105 | x | − | 1050 | − | 55 | x | + | 55 | × | 10 | − | 5 | x | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) |
| = | 105 | x | − | 1050 | − | 55 | x | + | 550 | − | 5 | x | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 |
| = | 50 | x | − | 500 | − | 5 | x | ( | x | − | 10 | ) | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) |
| = | 50 | x | − | 500 | − | 5 | x | x | + | 5 | x | × | 10 | + | 510 | ( | 21 | − | x | ) | − | 35 2 |
| = | 50 | x | − | 500 | − | 5 | x | x | + | 50 | x | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) |
| = | 100 | x | − | 500 | − | 5 | x | x | + | 510 | ( | 21 | − | x | ) | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) |
| = | 100 | x | − | 500 | − | 5 | x | x | + | 510 | × | 21 | − | 510 | x | − | 35 2 | ( | x | + | 20 | ) |
| = | 100 | x | − | 500 | − | 5 | x | x | + | 10710 | − | 510 | x | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) |
| = | - | 410 | x | + | 10210 | − | 5 | x | x | − | 35 2 | ( | x | + | 20 | ) | ( | 21 | − | x | ) |
| = | - | 410 | x | + | 10210 | − | 5 | x | x | − | 35 2 | x | ( | 21 | − | x | ) | − | 35 2 | × | 20 | ( | 21 | − | x | ) |
| = | - | 410 | x | + | 10210 | − | 5 | x | x | − | 35 2 | x | ( | 21 | − | x | ) | − | 350 | ( | 21 | − | x | ) |
| = | - | 410 | x | + | 10210 | − | 5 | x | x | − | 35 2 | x | × | 21 | + | 35 2 | x | x |
| = | - | 410 | x | + | 10210 | − | 5 | x | x | − | 735 2 | x | + | 35 2 | x | x | − | 350 |
| = | - | 1555 2 | x | + | 10210 | − | 5 | x | x | + | 35 2 | x | x | − | 350 | ( | 21 | − | x | ) |
| = | - | 1555 2 | x | + | 10210 | − | 5 | x | x | + | 35 2 | x | x | − | 350 | × | 21 | + | 350 |
| = | - | 1555 2 | x | + | 10210 | − | 5 | x | x | + | 35 2 | x | x | − | 7350 | + | 350 | x |
| = | - | 855 2 | x | + | 2860 | − | 5 | x | x | + | 35 2 | x | x |
| - | 855 2 | x | + | 2860 | − | 5 | x | x | + | 35 2 | x | x | = | 0 |