# math help: Hey, if you’re any good at math, I could really use your help. - Help.com

## Hey, if you’re any good at math, I could really use your help.

I have a math problem I just can’t seem to figure out. I googled it, but didn’t find anything that explained it well enough so that I understood the concept. That and some of the steps they put seemed to come out of no where.

The problem is 3 divided by 9 to the power of X and it all equals 243.
3/(9^X)=243

So what I have so far is that I tried to isolate X-

9^x(3/(9^x)=243)
3=2187^x
This is the xth root of - x|
So, then I took the xth root of the whole thing…
x|(3=2187^x)
x|(3)=2187

and I just don’t know where to go from there.

Does anyone know how to solve for X?

This open post was written 4 years, 9 months ago | V/U/S: 1,181, 8, 2 | Edit Post | Leave a reply | Report Post

### Reciprocity (0)

Since writing this post MaggieRae17 may have helped people, but has not within the last 4 days. MaggieRae17 is a verified member, has been around for 5 years, 1 month and has 18 posts and 417 replies to their name.

### Replies (8)

Where were you?

Click and drag to move the map around. FAQ: How we place people on this map »
You can also watch events on Help.com as they happen
Mouse over the map for 2 seconds to see an expanded, interactive view

> 3/(9^x) = 243

> 3 = 243 * 9^x

> 3/243 = 9^x

> log(3/243) / log(9) = x

> x = -2

Hm. Maybe the teacher should have mentioned we can do that. ;) Would have made life a lot easier. I’ve spent a couple of hours trying to figure this one out.

3/(9^x)=243
(9^x)=3/243
ln(9^x)=ln(3/243)
x.ln9=ln(3/243)
x=ln(3/243)/ln9
x=-2

Help me with: Insignificance.

Just out of curiousity, is there any way to do this one by hand?

Possibly I guess, maybe something to do with the threes (write 9=3*3) and then do a log with a different base than e or 10.

Help me with: Insignificance.

Ok, to do this one by hand-
From here
x|(3)=2187

3^(1/2)= 2187 ^ Y(Whatever the number is, once you reduce to the Greatest common factor)

Then assuming it’s 3, *So there are no more steps involved* you would subtract 1/2 from Y to get the answer. Which in this case is -2.

MaggieRae17 wrote:
Ok, to do this one by hand-
From here
x|(3)=2187

3^(1/2)= 2187 ^ Y(Whatever the number is, once you reduce to the Greatest common factor)

Then assuming it’s 3, *So there are no more steps involved* you would subtract 1/2 from Y to get the answer. Which in this case is -2.

Very good :)

Help me with: Insignificance.

=)

### Invite Others to Help

A logged in and verified Help.com member has the ability to setup a Friends List and invite others to help with posts.