Let some letter other than
, say
,
equal to
.
Then we have
. Substituting,
Factoring:
Use the zero factor principle.
Set the first factor = 0
Setting second factor = 0
Using first solution for
in
,
Take logs of both sides
Use rules of logarithms:
Divide both sides by
Get a calculator and punch out the left side:
That's one solution. We must also consider
the solution for t
to see if that
also yields a solution for x:
Using this solution for
in
.
.
No power of 3 can ever be negative, so we discard
the solution for
,
as extraneous.
The only solution is
, rounded to tenths is t=-.2
Edwin