is this logarithm undefined where

log 8 -4 + log 8 -2 = 1

i know that you cannot take the log of a negiative but if you combine the logarithms to

log 8 (-4x-2) = 1

log 8 8 = 1

1=1

therefore it satisifies.

is that an acceptable answer or is it incorrect?

if so why is it not allowed?