Question

Resolver: log (x-1) + log (x+1) = 3 log 2 + log (x-2)

Answer 1

log (x-1) + log (x+1) = 3log 2 + log (x-2)
log (x-1)·(x+1) = log 2³ + log (x-2)
log (x²-1) = log 8 + log (x-2)
log (x²-1) = log 8(x-2)
(x²-1) = 8(x-2)
x²-1 = 8x -16
x² -8x + 15 = 0    as raízes são x' = 3  e x'' = 5