| 100 | x | + | ( | 250 | − | x | ) | × | 80 | = | 250 | × | 195 2 |
| Left side of the equation = | 100 | x | + | 250 | × | 80 | − | x | × | 80 |
| = | 100 | x | + | 20000 | − | x | × | 80 |
| = | 20 | x | + | 20000 |
| 20 | x | + | 20000 | = | 250 | × | 195 2 |
| Right side of the equation = | 24375 |
| 20 | x | + | 20000 | = | 24375 |
| 20 | x | = | 24375 | − | 20000 |
| 20 | x | = | 4375 |
| x | = | 4375 | ÷ | 20 |
| = | 4375 | × | 1 20 |
| = | 875 | × | 1 4 |
| x | = | 875 4 |
| x | = | 218.75 |