| 4 | ( | x | ÷ | 10 | ) | − | 5 | ( | 2650 | − | x | ) | ÷ | 13 | = | 40 |
| Left side of the equation = | 4 | ( | x | ÷ | 10 | ) | − | 5 13 | ( | 2650 | − | x | ) |
| 4 | ( | x | ÷ | 10 | ) | − | 5 13 | ( | 2650 | − | x | ) | = | 40 |
| Left side of the equation = | 4 | x | ÷ | 10 | − | 5 13 | ( | 2650 | − | x | ) |
| = | 2 5 | x | − | 5 13 | ( | 2650 | − | x | ) |
| = | 2 5 | x | − | 5 13 | × | 2650 | + | 5 13 | x |
| = | 2 5 | x | − | 13250 13 | + | 5 13 | x |
| = | 51 65 | x | − | 13250 13 |
51 65 | x | − | 13250 13 | = | 40 |
51 65 | x | = | 40 | + | 13250 13 |
51 65 | x | = | 13770 13 |
| x | = | 13770 13 | ÷ | 51 65 |
| = | 13770 13 | × | 65 51 |
| = | 270 | × | 5 |
| x | = | 1350 |