Question

Log4 x + log4(x-12)= 3
Help??

Answer 1

Explanation:

log4(x) + log4(x - 12) = 3

log4[x(x - 12)] = log4(4³)

=> x(x - 12) = 4³

=> x² - 12x = 64

=> x² - 12x - 64 = 0

=> (x - 16)(x + 4) = 0

=> x = 16 or x = -4 (rejected as log of a negative number is undefined)

Hence x = 16.