Question

Nilai x yang memenuhi persamaan 2 log (x-2) + 2 log (x+4)=4

Answer 1

²log (x-2) + ²log (x+4) = 4
=> ²log (x-2) (x+4) = 4
=> ²log 16 = 4
Jadi, (x-2) (x+4) = 16
= x² + 2x -8 = 16
= x² + 2x - 8 - 16 = 0
= x² + 2x -24 = 0
= (x+6) (x-4) = 0
x + 6 = 0 atau x - 4 = 0
x = -6 atau x = 4

Semoga bermanfaat ^_^