bisa bantu nomor 5,6

1b
2c
maaf kalau salah

5) 2 log (2x - 4) - log (x - 1) < log (x + 4)
2 log (2x - 4) < log (x - 1) + log (x + 4)
log (2x - 4)² < log (x - 1)(x + 4)
log (4x² - 16x + 16) < log (x² + 3x - 4)
4x² - 16x + 16 < x² + 3x - 4
3x² - 19x + 20 < 0
(3x - 4)(x - 5) < 0
x = 4/3 atau x = 5
Garis bilangan
+++ (4/3) ---- (5) +++
Ambil daerah yang negatif

Syarat :
1) 2 log (2x - 4) => 2x - 4 > 0
=> 2x > 4
=> x > 2
2) log (x - 1) => x - 1 > 0
=> x > 1
3) log (x + 4) => x + 4 > 0
=> x > -4
Irisan garis bilangan
................ (4/3) xxxxxxxxxx (5) ......
.................................. (2) xxxxxxxxx
........ (1) xxxxxxxxxxxxxxxxxxxxxx
..(-4)xxxxxxxxxxxxxxxxxxxxxxxxx

Irisan HP = 2 < x < 5

6) log x² > log 3x + log 5
log x² > log 3x . 5
log x² > log 15x
x² > 15x
x² - 15x > 0
x(x - 15) > 0
x = 0 atau x = 15
Garus bilangan
+++ (0) ---- (15) +++
Ambil daerah yang positif

Syarat :
log 3x => 3x > 0 => x > 0

Irisan garis bilangan
xxxxx (0) ........ (15) xxxxxxx
........... (0) xxxxxxxxxxxxxxx
Irisan HP
= x > 15
= 15 < x