Tolong dibantu ya no 46 sama 47 :)

46) |B| = 2b(b) - (-8)b = 2b^2 + 8b
|A . B . A^-1| > 0
|A| . |B| . |A^-1| > 0
|A| . |B| . 1/|A| > 0
|B| > 0
2b^2 + 8b > 0
2b (b + 4) > 0
b = 0 atau b = -4
Garis bilangan
+++ (-4) --- (0) +++
b < -4 atau b > 0