Mathematics
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geerky42 (geerky42):
.
11 years ago
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geerky42 (geerky42):
@DarkBlueChocobo
11 years ago
geerky42 (geerky42):
\(\dfrac{2x}{4}-\dfrac{3}{4}\quad\Longleftrightarrow\dfrac{2x-3}{4}\)
11 years ago
OpenStudy (darkbluechocobo):
Hay there
11 years ago
OpenStudy (darkbluechocobo):
so then I went
11 years ago
OpenStudy (darkbluechocobo):
\[\frac{ 2x-3 }{ 4 }=\frac{ 10-15x }{ 6 }\]
11 years ago
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geerky42 (geerky42):
Yes, then you cross-multiply
11 years ago
OpenStudy (darkbluechocobo):
\[12x-18=40-60x\]
11 years ago
OpenStudy (darkbluechocobo):
\[72x-18=40\]
11 years ago
geerky42 (geerky42):
yeah
11 years ago
OpenStudy (darkbluechocobo):
\[72x=58\]
11 years ago
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geerky42 (geerky42):
Is that enough to tell what kind of equation it is?
11 years ago
geerky42 (geerky42):
you can tell that x is going to equal something, so it wont be indentity.
11 years ago
geerky42 (geerky42):
two other options are conditional equation and inconsistent equation
11 years ago
OpenStudy (darkbluechocobo):
Inconsistant i believe?
11 years ago
geerky42 (geerky42):
conditional equation
true for certain value of x, where if you simplify equation, you end up with x=4 or something
inconsistent equation
false equation, where you cannot solve for x.
11 years ago
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OpenStudy (darkbluechocobo):
Oh so conditional is just like a usual equation that works out ?
11 years ago
geerky42 (geerky42):
If you have something like x+1 = x+2, it's inconsistent equation because you end up with 1=2
11 years ago
geerky42 (geerky42):
yeah
11 years ago
OpenStudy (darkbluechocobo):
lel wow the facepalms are coming out today boys
11 years ago
OpenStudy (darkbluechocobo):
1c. 0=8 so this is false or inconsistent?
11 years ago
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geerky42 (geerky42):
pretty much both
11 years ago
OpenStudy (darkbluechocobo):
I am having many issues on 2a
11 years ago
geerky42 (geerky42):
inconsistent equation is kind of fancy way to say false equation lol
11 years ago
geerky42 (geerky42):
you would need to combine fraction on right side.
To do so, you need to get denominator to be same
11 years ago
geerky42 (geerky42):
you have \(y-2\) and \(y+1\)
So you just multiply numerator and denominator by \(y+1\) for first fraction and \(y-2\) for second
11 years ago
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geerky42 (geerky42):
\[\dfrac{1}{y-2}-\dfrac{2}{y+1}\quad\longrightarrow\dfrac{y+1}{y+1}\cdot\dfrac{1}{y-2}-\dfrac{2}{y+1}\cdot\dfrac{y-2}{y-2}\]
11 years ago
geerky42 (geerky42):
Does that make sense?
Basically you just need to get denominator to be same, so you just multiply numerator and denominator by something that would get you to desired denominator
11 years ago
geerky42 (geerky42):
kinda hard for me to explain lol
11 years ago
OpenStudy (darkbluechocobo):
so 1/(y+1)(y-2) - 4/(y+1)(y-2) ?
11 years ago
geerky42 (geerky42):
\[\dfrac{y+1}{y+1}\cdot\dfrac{1}{y-2}-\dfrac{2}{y+1}\cdot\dfrac{y-2}{y-2}\\~\\= \dfrac{y+1}{(y+1)(y-2)} - \dfrac{2(y-2)}{(y+1)(y-2)}\\~\\=\dfrac{y+1-2(y-2)}{(y+1)(y-2)}\]
11 years ago
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geerky42 (geerky42):
ok let's start with something simply.
\(\dfrac{1}{6}+\dfrac{1}{2}\)
How can we combine fraction here?
11 years ago
OpenStudy (darkbluechocobo):
multiply by 3/3
11 years ago
OpenStudy (darkbluechocobo):
so 1/6+1/2*3/3
11 years ago
OpenStudy (darkbluechocobo):
so you would get 1/6+3/6
11 years ago
geerky42 (geerky42):
right, so for problem 2a. it's same idea, just with variable.
11 years ago
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geerky42 (geerky42):
get what I am saying here?
11 years ago
OpenStudy (darkbluechocobo):
Yes I do its just weird for me to visualize and see it right away t-t idk why
11 years ago
geerky42 (geerky42):
because it's something new for you, I guess?
11 years ago
OpenStudy (darkbluechocobo):
Well like the bigness of the equation kinda like put me in my place kinda deal
11 years ago
geerky42 (geerky42):
ok, so now we have \[\dfrac{y+1-2(y-2)}{(y+1)(y-2)}\]
simplify numerator
11 years ago
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OpenStudy (darkbluechocobo):
\[y+1-2y+4\]
11 years ago
geerky42 (geerky42):
CLEP test seem little harsh lol...
11 years ago
geerky42 (geerky42):
don't forgot combine like term
11 years ago
OpenStudy (darkbluechocobo):
yeh was just showing steps
11 years ago
OpenStudy (darkbluechocobo):
-y+5
11 years ago
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OpenStudy (darkbluechocobo):
It does seem harsh :/ I'm gonna like work myself to the point of no return so I do well on it . I want this
11 years ago
geerky42 (geerky42):
Right.
Now cross multiply
\[\dfrac{7}{y^2-y-2} = \dfrac{-y+5}{(y-2)(y+1)}\longrightarrow~?\]
11 years ago
OpenStudy (darkbluechocobo):
so we have to do the same with the other side then get (y-2)(y+1) as denominator?
11 years ago
OpenStudy (darkbluechocobo):
oh i guess we dont
11 years ago
geerky42 (geerky42):
Not really. denominator doesn't matter if they are on different side of equation.
11 years ago
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OpenStudy (darkbluechocobo):
\[y^2(-y+5) ,-y(-y+5),-2(-y+5)\] would this work?
11 years ago
OpenStudy (darkbluechocobo):
so I got -y3 + 5y^2
y^2 + 5y
2y+10
11 years ago
OpenStudy (darkbluechocobo):
before combining
11 years ago
geerky42 (geerky42):
-y^3 + 5y^2
y^2 - 5y
2y-10
11 years ago
OpenStudy (darkbluechocobo):
damn i messed up multiplying
11 years ago
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geerky42 (geerky42):
you just messed up with +/- signs
11 years ago
OpenStudy (darkbluechocobo):
\[-y^2+6y^2-3y-10\]
11 years ago
geerky42 (geerky42):
yeah
11 years ago
OpenStudy (darkbluechocobo):
now the other side
11 years ago
OpenStudy (darkbluechocobo):
let me delete that i need to slow down
11 years ago
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OpenStudy (darkbluechocobo):
7(y+1)
7(y-2)
14y+7, 14y-14
14y+14y, 7-14
11 years ago
geerky42 (geerky42):
none. left side should start with \(7(y+1)(y-2)\)
11 years ago
OpenStudy (darkbluechocobo):
so just keep it as is o.o?
11 years ago
geerky42 (geerky42):
So firstly, you expand \((y+1)(y-2)\)
11 years ago
OpenStudy (darkbluechocobo):
why not work out?
11 years ago
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geerky42 (geerky42):
You only distribute something with plus sign.
\(a(b+c) = ab+ac\)
But \(a(bc) = abc\)
11 years ago
OpenStudy (darkbluechocobo):
Alrights
11 years ago
geerky42 (geerky42):
make sense?
11 years ago
OpenStudy (darkbluechocobo):
Yes it does
11 years ago
OpenStudy (darkbluechocobo):
y^2+-2y+y-2?
11 years ago
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geerky42 (geerky42):
Yeah
11 years ago
OpenStudy (darkbluechocobo):
so we have \[y^2-y-2=-y^3+6y^2-3y-10\]
11 years ago
geerky42 (geerky42):
you forgot 7
11 years ago
geerky42 (geerky42):
\[7(y^2-y-2)=-y^3+6y^2-3y-10\]
11 years ago
OpenStudy (darkbluechocobo):
damn
11 years ago
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OpenStudy (darkbluechocobo):
so do we expand it out with 7 now?
11 years ago
geerky42 (geerky42):
yup
11 years ago
geerky42 (geerky42):
\[7y^2-7y-14=-y^3+6y^2-3y-10\]
11 years ago
OpenStudy (darkbluechocobo):
I got that
11 years ago
geerky42 (geerky42):
now take all terms to right side;
\(0 = -y^3-y^2+4y-4\)
11 years ago
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OpenStudy (darkbluechocobo):
can confirm got that after working out
11 years ago
OpenStudy (darkbluechocobo):
lel sorry I doing this in a note book :p
11 years ago
geerky42 (geerky42):
know what to do from here?
11 years ago
geerky42 (geerky42):
Notice something you can factor out?
Hint: \[0 = \boxed{-y^3-y^2}+\boxed{4y-4}\]
11 years ago
OpenStudy (darkbluechocobo):
we can simplify ?
11 years ago
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OpenStudy (darkbluechocobo):
oh you asked lol
11 years ago
geerky42 (geerky42):
Oops should be \(0 = -y^3-y^2+4y+4\)
11 years ago
OpenStudy (darkbluechocobo):
would we simplify the y's?
11 years ago
geerky42 (geerky42):
well, actually we try to factor, so we can easily figure out solutions.
11 years ago
OpenStudy (darkbluechocobo):
-1(y^2+4)(y+1)
11 years ago
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OpenStudy (darkbluechocobo):
Would that be how we factor it?
11 years ago
geerky42 (geerky42):
close. should be \((y+1)(4-y^2)\)
11 years ago
geerky42 (geerky42):
Then you can factor \(4-y^2\)
11 years ago
geerky42 (geerky42):
or you can "factor out" -1 from \(4-y^2\)
So you would have something like \((-1)(y^2-4)\)
11 years ago
OpenStudy (darkbluechocobo):
-y^2+4. Doesnt this just put us back where we were?
11 years ago
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geerky42 (geerky42):
Yeah, just to make it slightly easier to factor out, but never mind.
11 years ago
geerky42 (geerky42):
factoring -1 out is just optional.
11 years ago
geerky42 (geerky42):
You got \(0 = (y+1)(2-y)(y+2)\)?
11 years ago