| ( | 8 | + | m | ) | ( | 200 | − | 5 | m | ) | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) | − | 4000 | = | 700 |
| Left side of the equation = | 8 | ( | 200 | − | 5 | m | ) | + | m | ( | 200 | − | 5 | m | ) | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) | − | 4000 |
| = | 8 | × | 200 | − | 8 | × | 5 | m | + | m | ( | 200 | − | 5 | m | ) | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) | − | 4000 |
| = | 1600 | − | 40 | m | + | m | ( | 200 | − | 5 | m | ) | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) | − | 4000 |
| = | - | 2400 | − | 40 | m | + | m | ( | 200 | − | 5 | m | ) | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) |
| = | - | 2400 | − | 40 | m | + | m | × | 200 | − | m | × | 5 | m | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) |
| = | - | 2400 | + | 160 | m | − | m | × | 5 | m | + | ( | 8 | + | m | ) | ( | 300 | − | 10 | m | ) |
| = | - | 2400 | + | 160 | m | − | m | × | 5 | m | + | 8 | ( | 300 | − | 10 | m | ) | + | m | ( | 300 | − | 10 | m | ) |
| = | - | 2400 | + | 160 | m | − | m | × | 5 | m | + | 8 | × | 300 | − | 8 | × | 10 | m | + | m |
| = | - | 2400 | + | 160 | m | − | m | × | 5 | m | + | 2400 | − | 80 | m | + | m | ( | 300 | − | 10 | m | ) |
| = | - | 0 | + | 80 | m | − | m | × | 5 | m | + | m | ( | 300 | − | 10 | m | ) |
| = | - | 0 | + | 80 | m | − | m | × | 5 | m | + | m | × | 300 | − | m | × | 10 | m |
| = | - | 0 | + | 380 | m | − | m | × | 5 | m | − | m | × | 10 | m |
| - | 0 | + | 380 | m | − | m | × | 5 | m | − | m | × | 10 | m | = | 700 |
| m2= | 70 3 |