7log (x - 5) + 7log ( x + 1) = 1

(x - 5)(x + 1) = 7
x² - 4x - 5 = 7
x² - 4x - 12 = 0
(x - 6)(x + 2) = 0
x = 6 atau x = -2

Numerus harus positif maka x = 6

Bab Logaritma
Matematika SMA Kelas X

^ = pangkat

^7log (x - 5) + ^7log (x + 1) = 1
^7log ((x - 5)(x + 1)) = 1
x² - 4x - 5 = 7^1
x² - 4x - 5 - 7 = 0
x² - 4x - 12 = 0
(x - 6) (x + 2) = 0
x - 6 = 0
x = 6

x + 2 = 0
x = -2

syarat
x - 5 > 0
x > 5

Penyelesaian
x = 6