pekka16
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| Joined: 19 May 2013 |
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| 16 Dec 2014 05:28 AM |
I'm having problems with 2 step linear equations
In the problem 7(2y-3)=3(6y+5) which becomes 14y-21=18y+15 And then I don't know what to do anymore |
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pekka16
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pekka16
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pekka16
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| 16 Dec 2014 05:30 AM |
i think it's 14y-18y=21+15 -4y=36 y=9? |
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pekka16
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67thave
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| 16 Dec 2014 05:30 AM |
14y-21=18y+15
subtract 14y on both sides
it becomes -21 = 4y + 15 subtract 15 on both sides
now it's -36 = 4y
So y is equal to -9 |
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| 16 Dec 2014 05:31 AM |
| i personally think that it's 9 |
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pekka16
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| 16 Dec 2014 05:32 AM |
@yoshi if it's 9 it becomes 105=177 |
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| 16 Dec 2014 05:32 AM |
| -4y=36, is the answer, if I'm correct? |
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| 16 Dec 2014 05:32 AM |
14y-21=18y+15 -14y -14y ------------- -21=4y+15 -15 -15 ---------- -36=4y ------- 4
y = -9 |
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| 16 Dec 2014 05:32 AM |
| ehm no wait I posted nonsense nvm |
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pekka16
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| 16 Dec 2014 05:33 AM |
Well since that've says say too Please tell me how to do it This a part of my exam |
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pekka16
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| 16 Dec 2014 05:33 AM |
| 36 didn't work that was my first answer. |
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| 16 Dec 2014 05:34 AM |
so take the original equation
7(2y-3)=3(6y+5)
and substitute
7(2(-9)-3) = 3(6(-9)+5)
7(-18-3) = 3(-54 + 5)
7(-21) = 3(-49)
147 = 147 |
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| 16 Dec 2014 05:34 AM |
14y-21=18y+15
14y=18y+36
4y = -36
y = -9
ez pz
lrn2math |
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| 16 Dec 2014 05:37 AM |
| crap i'm getting confused with my current lesson and linear equations |
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pekka16
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| 16 Dec 2014 05:40 AM |
Does that always work because what the book says in a sample problem like 5v-4=7v+10 -------------------- 5v-4-7v=7v+10-7v -------------------------- -2v-4=10 -------------- -2v-4+4=10+4 -------------------- V=-7 I don't know how it happened please explain |
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| 16 Dec 2014 05:41 AM |
-9
had to crack open the good ol' alg 1 textboox |
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| 16 Dec 2014 05:48 AM |
14y-21=18y+15
First, subtract 14y on both sides.
-21=4y+15
Now subtract 15 from both sides
-36=4y
Divide both sides by 4
Y=-9
Respect the science! |
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pekka16
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| 16 Dec 2014 05:56 AM |
| How don you know that you are supposed to use 14y and 15 to subtract that is the big question in my mind. |
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pekka16
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pekka16
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| Joined: 19 May 2013 |
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pekka16
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| Joined: 19 May 2013 |
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pekka16
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| Joined: 19 May 2013 |
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