³log(x-4) + ³log(x-4) = 2

ingat! log a + log b = log (a × b)

³log (x - 4) + ³log (x - 4) = 2

³log (x - 4) + ³log (x - 4) = ³log 3²

hilangkan ³log maka akan diperoleh :

(x - 4) (x - 4) = 9

x² - 8x + 16 = 9

x² - 8x + 16 - 9 = 0

x² - 8x + 7 = 0

(x - 7) (x - 1) = 0

x = 7 atau x = 1