Tentukan nilai x yang memenuhi : a.) Log (x + 1) - Log (x - 1) = log 3 b.) 5 log (x + 1) + 5 log(x - 3) = 5 log 5

Semoga bermanfaat, terima kasih

A. Log (x + 1) - Log (x - 1) = log 3

Sesuai sifat logaritma log a - log b = log a/b

Maka

Log (x + 1) - Log (x - 1) = log 3
Log (x+1)/(x-1) = log 3

(x+1)/(x-1) = 3
x+1 = 3x-3
-2x = -4
x = 2

B. 5 log (x + 1) + 5 log(x - 3) = 5 log 5

Sesuai sifat logaritma log a + log b = log ab

Maka

5 log (x + 1) + 5 log(x - 3) = 5 log 5
5 log (x+1)(x-3) = 5 log 5

(x+1)(x-3) = 5
x² - 2x - 3 = 5
x² - 2x - 8 = 0
( x - 4 ) ( x + 2 ) = 0

x - 4 = 0
x = 4

Dan

x + 2 = 0
x = -2

Semoga jelas ya kak