crescentcitycid wrote:...there is one I'm not sure about.
Can that go any further than b.9 ?
Yes. In fact, avoid that entirely. Instead of simplifying the exponent on
, try setting up and solving an exponential equation
:. . . . .
...for some numerical value
Then:. . . . .
Apply a log rule
to get:. . . . .
Simplify the left-hand side, and the answer should pop out at you.