Question

Solve log3x +log9 = 0

Answer 1

write the left hand side as one log expression

Answer 2

Log(27x) = 0 ?

Answer 3

then use the following:
\[\log_a(1)=0 \\ \text{ so if you have } \log_a(f(x))=0 \text{ then } f(x)=1 \]

Answer 4

\[
\begin{align*}
\log{3x} + \log{9} &= 0\\
\log{(3\cdot9)x} &= 0\\
10^{\log{27x}} &= 10^0\\
27x &= 1\\
x &= \frac{1}{27}
\end{align*}
\]

Answer 5

The above assumes log base 10, replace ten with any other base you use.

Answer 6

Yeah that's what I got but that's not one of my answer choices @adolm

Answer 7

what are the choices?

Answer 8

decimal format?

Answer 9

maybe they want you to round your answer to like the nearest hundredth or something?

Answer 10

if so 1/27 wouldn't be appropriate
because it is exact form

Answer 11

Maybe. That would be weird in algebra though.

Answer 12

you could divide 1 by 27 though

Answer 13

Yeah still not it.. @myininaya

Answer 14

What are the options?

Answer 15

a. 27 b. 0.04 c.3 d. 0.33
a is wrong btw..

Answer 16

It's b:
\[
\frac{1}{27} \approx 0.0370370 \approx 0.04 \text{(rounded)}
\]

Answer 17

ohh.. that makes sense....

Answer 18

Not the best answers.