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# Logs watch

1. (Original post by jacksonmeg)
(X+1)log2 - (3x-2)log3 = 0 :/
This is fine

log2 and log3 are just numbers

If you can solve 7(x+1) - 5(3x-2) then you can solve this

Think about what you would do but instead of 7 you have the number log2 and, instead of 5 you have the number log3
2. (Original post by jacksonmeg)
Idk :/ none of the rules I've got seem to work
Ignore log rules for now.
Just look at it as an algebra question
3. Multiply out the brackets and solve x
but what would you get when you times log2 by x
4. (Original post by jacksonmeg)
Multiply out the brackets and solve x
Exactly
5. Idk how to expand it lol
6. (Original post by jacksonmeg)
Idk how to expand it lol
Use if it makes the expansion easier for you.
as TenOfThem says, it's just a number.
7. (Original post by joostan)
Use if it makes the expansion easier for you.
as TenOfThem says, it's just a number.
I don't know what you mean, I don't really know anything about logs
8. Is it like xlog2 + log2 -3xlog3 + 2log3?
9. (Original post by jacksonmeg)
Is it like xlog2 + log2 -3xlog3 + 2log3?
yes
10. I did. X -3x = - 1 -2
X= 1.5. But it's wrong
11. (Original post by jacksonmeg)
I did. X -3x = - 1 -2
X= 1.5. But it's wrong
12. (Original post by jacksonmeg)
I did. X -3x = - 1 -2
X= 1.5. But it's wrong
Could you post everything you've done, cos it's hard to see where it is you're confused.
13. Sry I'm typing on an iPad, I moved log2 and 2log3 to the other side making them a minus, then divded -log2by log2 leaving x on its own and -2log3 by log3 leaving -3x on its own
14. (Original post by jacksonmeg)
Sry I'm typing on an iPad, I moved log2 and 2log3 to the other side making them a minus, then divded -log2by log2 leaving x on its own and -2log3 by log3 leaving -3x on its own
You cannot divide like that. You cannot divide one term and leave the other undivided lol.

You have to take x out as a factor and then move the factor across.
15. I'll leave it then and ask in school tomorrow, need to go to sleep. Thanks for your help
16. (Original post by jacksonmeg)
Sry I'm typing on an iPad, I moved log2 and 2log3 to the other side making them a minus, then divded -log2by log2 leaving x on its own and -2log3 by log3 leaving -3x on its own
So you said:

Now isolate x by factoring it out e.g
17. (log2-3log3)x + log2 -2log 3= 0 ?
18. i did (log2-3log3)x = -log2 + 2log3
x = -log2 + 2 log3 / (log 2 - 3log3)

it didnt work :l what did i do wrong?
19. (Original post by jacksonmeg)
i did (log2-3log3)x = -log2 + 2log3
x = -log2 + 2 log3 / (log 2 - 3log3)

it didnt work :l what did i do wrong?
? - It's very slightly wrong - a sign error has been made.
It's worth noting that using a different log base would give you an answer that looked different, but numerically would be identical.
Spoiler:
Show
By the way if you want me to reply, it helps if you quote me - it makes it easier to notice.
20. (Original post by joostan)
? - It's very slightly wrong - a sign error has been made.
It's worth noting that using a different log base would give you an answer that looked different, but numerically would be identical.
Spoiler:
Show
By the way if you want me to reply, it helps if you quote me - it makes it easier to notice.
im getting -0.57 but the book says 1.11

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Updated: May 15, 2013
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