s | ( | s | + | 2 | ) | ( | s | + | 4 | ) | + | 1 | = | 0 |
Left side of the equation = | s | s | ( | s | + | 4 | ) | + | s | × | 2 | ( | s | + | 4 | ) | + | 1 |
= | s | s | s | + | s | s | × | 4 | + | s | × | 2 | ( | s | + | 4 | ) | + | 1 |
= | s | s | s | + | s | s | × | 4 | + | s | × | 2 | s | + | s | × | 2 | × | 4 |
= | s | s | s | + | s | s | × | 4 | + | s | × | 2 | s | + | s | × | 8 | + | 1 |
s | s | s | + | s | s | × | 4 | + | s | × | 2 | s | + | 8 | s | + | 1 | = | 0 |