| s | s | ( | 1 25 | s | s | + | 1 | ) | ( | 1 100 | s | s | + | 1 | ) | = | 900 |
| Left side of the equation = | s | s | × | 1 25 | s | s | ( | 1 100 | s | s | + | 1 | ) | + | s | s | × | 1 | ( | 1 100 | s | s | + | 1 | ) |
| = | s | s | × | 1 25 | s | s | × | 1 100 | s | s | + | s | s | × | 1 25 | s |
| = | s | s | × | 1 2500 | s | s | s | s | + | s | s | × | 1 25 | s | s |
| = | s | s | × | 1 2500 | s | s | s | s | + | s | s | × | 1 25 | s | s |
| = | s | s | × | 1 2500 | s | s | s | s | + | s | s | × | 1 25 | s | s |
| s | s | × | 1 2500 | s | s | s | s | + | s | s | × | 1 25 | s | s | = | 900 |