Question

Tentukan nilai x !
kasih cara yang mudah dipahami ya :)

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

Answer 1

Log(x + 1) - log(x - 1) = log 3
log((x + 1)/(x - 1)) = log 3      "karena basisnya sama (10), bisa gunakan sifat a log b - a log c = a log (b/c)"
log ((x + 1)/(x - 1)) = log 3  "basisnya sama, berarti (x+1)/(x-1) = 3"
(x + 1)/(x - 1) = 3
(x + 1) = 3(x - 1)
x + 1 = 3x - 3
1 + 3 = 3x - x
4 = 2x
x = 2