| ( | 80 | + | x | ) | + | 50 | x | + | 80 | × | 50 | = | 5400 |
| Left side of the equation = | ( | 80 | + | x | ) | + | 50 | x | + | 4000 |
| ( | 80 | + | x | ) | + | 50 | x | + | 4000 | = | 5400 |
| Left side of the equation = | 80 | + | x | + | 50 | x | + | 4000 |
| = | 4080 | + | 51 | x |
| 4080 | + | 51 | x | = | 5400 |
| 51 | x | = | 5400 | − | 4080 |
| 51 | x | = | 1320 |
| x | = | 1320 | ÷ | 51 |
| = | 1320 | × | 1 51 |
| = | 440 | × | 1 17 |
| x | = | 440 17 |
| x | = | 25.882353 |