Question

Desperate! :(
Solve for X
Not multiple choice

Answer 1

5=log_3(x^2+18)

Answer 2

I only got this far\[5=\frac{ \log(x^2+18) }{ \log3}\]

Answer 3

\[\Large 5 = \log_3(x^2+18)\]
\[\Large 3^5 = x^2+18\]
\[\Large 243 = x^2+18\]
\[\Large 0 = x^2+18-243\]
\[\Large x^2+18-243 = 0\]
I'll let you finish

Answer 4

15

Answer 5

? I'm not sure that coordinates with what I've learned. There's no inversing logaritthms

Answer 6

you should get 2 solutions

Answer 7

15 is not one of the solutions

Answer 8

oh nvm, made a typo

Answer 9

I'm getting x = 15 or x = -15 which sounds like what you got

Answer 10

I'm just unsure hoe the log went away, what property did you use?

Answer 11

how*

Answer 12

logs undo exponents and vice versa

I used this rule

http://study.com/cimages/multimages/16/logform3j.jpg

Answer 13

Ah! I see. ok so it is\[\pm15\]

Answer 14

I have another that I was hoping you'd check

Answer 15

go ahead

Answer 16

-2=log(3x+5)
10^-2=3x+5
.01=3x+5
.01-5=3x+5-5
-4.99=3x
-4.99/3=x

Answer 17

then just calculate what -4.99/3 is equal to

Answer 18

or you can think of 0.01 as 1/100

Answer 19

so then that's correct? I feel uneasy about it

Answer 20

does your teacher want the answer as a fraction? or decimal?

Answer 21

she didn't specify "solve each equation for x" is all it says

Answer 22

so I'd then write both just to be on the safe side

Answer 23

ok thank you

Answer 24

no problem