| −12 − 4x | −3 | 1 | |||
≥ | − | ||||
| 9 + x2 | x + 1 | x − 3 |
| − 12 − 4 x | −3 | 1 | |||
≥ | − | x ≠ − 1 i x ≠ 3 | |||
| 9 + x2 | x + 1 | x − 3 |
| 4 x + 12 | 3 | 1 | |||
≤ | + | ||||
| x2 + 9 | x + 1 | x −3 |
| 4 x + 12 | 3 x − 9 + x + 1 | ||
− | ≤ 0 | ||
| x2 + 9 | (x + 1)*(x −3) |
| 4 x + 12 | 4 x − 8 | ||
− | ≤ 0 | ||
| x2 + 9 | (x + 1)*( x − 3) |
| ( 4 x + 12)*(x + 1)*( x −3) − ( x2 + 9)*( 4 x − 8) | |
≤ 0 | |
| (x2 + 9)*( x + 1)*(x − 3) |