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General => The Lobby => Topic started by: Nyerp on September 29, 2010, 04:03:58 PM

Title: help
Post by: Nyerp on September 29, 2010, 04:03:58 PM
2 log7(x + 8) - log7(49) = 2

solve itttttttttttttttt

i don't get it
Title: Re: help
Post by: Thyme on September 29, 2010, 04:08:47 PM
41 5thgrade;
Title: Re: help
Post by: Nyerp on September 29, 2010, 04:09:20 PM
Quote from: Thyme on September 29, 2010, 04:08:47 PM
41 5thgrade;


show me ur proof
Title: Re: help
Post by: Nyerp on September 29, 2010, 04:09:54 PM
how the fuck did you do that?!?! are you magic????
Title: Re: help
Post by: ikanaide on September 29, 2010, 04:12:21 PM
sorry, I never really understand logarithims either. ~_~
Title: Re: help
Post by: Nyerp on September 29, 2010, 04:12:35 PM
u prolly just put it into wolframalpha >:|
Title: Re: help
Post by: Thyme on September 29, 2010, 04:21:28 PM
Quote from: Nyerp on September 29, 2010, 04:12:35 PM
u prolly just put it into wolframalpha >:|


lol yeah giggle;
Title: Re: help
Post by: Nyerp on September 29, 2010, 04:23:52 PM
does anyone know how to actually do it
Title: Re: help
Post by: ME## on September 29, 2010, 04:26:42 PM
i'm 'doing' it


am i doing it right?  we'll see
Title: Re: help
Post by: Nyerp on September 29, 2010, 04:39:19 PM
argh the next question is bullshit and it won't accept my answer
Title: Re: help
Post by: Thyme on September 29, 2010, 04:40:36 PM
Quote from: Nyerp on September 29, 2010, 04:39:19 PM
argh the next question is bullshit and it won't accept my answer


I miss the good old days of pen and paper. The paper would accept your answer no matter what. :'(
Title: Re: help
Post by: [REDACTED] on September 29, 2010, 05:00:04 PM
Quote from: Nyerp on September 29, 2010, 04:03:58 PM
2 log7(x + 8) - log7(49) = 2

solve itttttttttttttttt

i don't get it

<=>
log7(x + 8)2 - 2 = 2
<=>
log7(x + 8)2=4
<=>
(x+8)2=74
<=>
x+8=49
<=>
x=41
Title: Re: help
Post by: Nyerp on September 29, 2010, 05:29:43 PM
oh wow i completely ignored the fact that log7(49) is perfectly solvable goowan

now do this one felty: n_n

log(x + 8) = 1 - log(x - 7)

Quote from: Thyme on September 29, 2010, 04:40:36 PM
I miss the good old days of pen and paper. The paper would accept your answer no matter what. :'(


me too myface;

[spoiler]it was actually 4 months ago in high school where i actually learned things >:[[/spoiler]
Title: Re: help
Post by: ????? on September 29, 2010, 07:08:20 PM
Quote from: Nyerp on September 29, 2010, 05:29:43 PM
log(x + 8) = 1 - log(x - 7)

10^(x+8)=1-10^(x-7)
solve as normal
Title: Re: help
Post by: Nyerp on September 29, 2010, 07:12:41 PM
Quote from: TheSequel on September 29, 2010, 07:08:20 PM
10^(x+8)=1-10^(x-7)
solve as normal


doesn't work like that bro
Title: Re: help
Post by: ????? on September 29, 2010, 07:22:15 PM
Quote from: Nyerp on September 29, 2010, 07:12:41 PM
doesn't work like that bro

log(y) = log10(y)
lobb(y)=x

log(x + 8) = 1 - log(x - 7)
10(x+8)=1-10(x-7)

Why can't it be rewritten like that?
Title: Re: help
Post by: Nyerp on September 29, 2010, 08:04:40 PM
Quote from: TheSequel on September 29, 2010, 07:22:15 PM
log(y) = log10(y)
lobb(y)=x

log(x + 8) = 1 - log(x - 7)
10(x+8)=1-10(x-7)

Why can't it be rewritten like that?


lobb(y)=x

to change that to an exponential equation, it's bx=y, not whatever the hell you just did

you also can't switch to exponential in this case until you combine the logs

so there
Title: Re: help
Post by: [REDACTED] on September 29, 2010, 09:33:05 PM
holy shit. nyerp is right.
Title: Re: help
Post by: Nyerp on September 29, 2010, 09:42:44 PM
Quote from: Quis sum? on September 29, 2010, 09:33:05 PM
holy shit. nyerp is right.


what

also answer my other question!! plz
Title: Re: help
Post by: [REDACTED] on September 30, 2010, 06:46:42 PM
Quote from: Nyerp on September 29, 2010, 05:29:43 PM
oh wow i completely ignored the fact that log7(49) is perfectly solvable goowan

now do this fuck felty: n_n

log(x + 8) = 1 - log(x - 7)

me too myface;

[spoiler]it was actually 4 months ago in high school where i actually learned things >:[[/spoiler]

<=>log(x+8)=log(10)-log(x-7)
<=>log(x+8)=log(10/(x-7))
<=>x+8=10/(x-7)
(x+8)(x-7)=10
x^2+x-56=10
x^2+x-66=0
use quad. formula.
Title: Re: help
Post by: Nyerp on September 30, 2010, 07:10:21 PM
i found the problem i was having

[spoiler]i had read the quadratic formula wrong lol goowan[/spoiler]

thanks giggle;

but stick around cuz i might need more help akudood;
Title: Re: help
Post by: Nyerp on September 30, 2010, 07:25:47 PM
log(x3) = (log(x))2

where did you gooooooooooo
Title: Re: help
Post by: [REDACTED] on September 30, 2010, 08:06:32 PM
Quote from: Nyerp on September 30, 2010, 07:25:47 PM
log(x3) = (log(x))2

where did you gooooooooooo
3log(x)=(log(x))2. Let u=log(x). then 3u=u3. u=0, -sprt(3), sqrt(3). Find the extraneous roots and don't take them into consideration. Find x for each possible u.
Title: Re: help
Post by: Nyerp on September 30, 2010, 08:33:25 PM
just give me the highest zero >.<

ALSO WHAT THE FUCK DOES THE LEWIS STRUCTURE OF A HYPONITRITE ION LOOK LIKE smithicide;
Title: Re: help
Post by: Kalahari Inkantation on September 30, 2010, 09:08:17 PM
(http://i52.tinypic.com/235tw2.png)

cjlubdoods;
Title: Re: help
Post by: Nyerp on September 30, 2010, 09:41:30 PM
my answer was right already but lol thanks cjlubdoods;
Title: Re: help
Post by: [REDACTED] on September 30, 2010, 09:47:08 PM
I borked that up. u^2-3u=0. u=0,3
Title: Re: help
Post by: Nyerp on September 30, 2010, 09:52:22 PM
so the zeros are 1 and 1000

yay i got it right

thanks giggle;
Title: Re: help
Post by: Classic on September 30, 2010, 09:52:52 PM
I hate math.