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**Gabrielle****Guest**

Ive done these multiple times and I feel like giving up. I don't understand what my teacher is saying.

#8

y=(1/2)x-3

y=(3/2)x-1

y=(1/2x-3

(3/2)x-1=(1/2)x-3

+1 +1

(3/2)x=(1/2)x-2

(4/2)x= -2

4x = -2

x= -2

y=(3/2)x-1

y=(3/2)-2-1

y=-3-1

y= -4

(-2,-4)

#12

4x + 3y= -15

y=x+2

4x+3(x+2)=-15

4x+3x+6=-15

7x=-21

x=-3

y=x+2

y=-3+2

y=-1

(-3,-1)

#16

y=-2x+1

y=x-5

y=3x+6

x=2

y-6=3x

y=-3x

(2,-3)

and this is what my teacher said...

#8 - Tell me what you did to get from the first step to the second.

(3/2)x=(1/2)x-2

(4/2)x= -2

#12 - The work must show elimination. You have used substitution. Try again.

#16 - I don't see your elimination work. Please look at the example that I provided in my last post to help you show your work for #12 and #16.

she gave me this example but im not sure how to put my problems like this

Your work doesn't flow very well. You do not need to fix this one, but take a look at the proper way to show your work.

x + 2y = -4 Already in standard form.

4y = 3x + 12 Write in standard form.

--------

x + 2y = -4

-3x + 4y = 12 Now determine what you need to multiply the equations by.

--------

3(x + 2y = -4)

3x + 6y = -12

-3x + 4y = 12 Now add the equations together to eliminate the x's.

------------------

10y = 0

y = 0 Substitute 0 for y in one of the original equations.

-----------------

x + 2y = -4

x + 2(0) = -4

x = -4

(-4, 0)

Hi;

What sort of help can We provide you?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 87,238

Hi;

The question has already been answered by bob bundy.

http://www.mathisfunforum.com/viewtopic … 82#p326582

Please go there.

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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