| ( | x | + | 999 | ) | ÷ | 7 | = | 99 | × | 9 |
| Left side of the equation = | x | × | 1 7 | + | 999 | × | 1 7 |
| = | x | × | 1 7 | + | 999 7 |
1 7 | x | + | 999 7 | = | 99 | × | 9 |
| Right side of the equation = | 891 |
1 7 | x | + | 999 7 | = | 891 |
1 7 | x | = | 891 | − | 999 7 |
1 7 | x | = | 5238 7 |
| x | = | 5238 7 | ÷ | 1 7 |
| = | 5238 7 | × | 7 |
| = | 5238 | × | 1 |
| x | = | 5238 |