Inactive Tutor answered • 11/20/13
Tutor
New to Wyzant
Hi Trinity;
I assume this is...
(-1/2)x + (1/8)y = 3/4
Let's eliminate the fractions...
Let's note the fact that the denominators, also known as divisors, are 2, 8 and 4. Let's multiply everything by 8...
8[(-1/2)x + (1/8)y] = 8(3/4)
-4x+y=6
If you would like this in the format of y=mx+b such that you can easily graph it, then let's move the -4x from the left side to the right where it becomes positive...
y=4x+6
The slope of this line, change of y divided by change of x, is 4.
The y-intercept, value of y when x=0, is 6.
Does this help, or is there more to this question?
Inactive Tutor
Let's do what your book says, almost...
(-1/2)x + (1/8)y = 3/4
Let's add, not subtract, (1/2)x to both sides of the equation...
We must add because the negative (1/2)x is already on the left side of the equation. We need to cancel it as we proceed to isolate y...
(1/2)x-(1/2)x+(1/8)y=(1/2)x+3/4
(1/8)y=(1/2)x+3/4
Now we can multiply both sides by 8, not divide by 8...
(8)(1/8)y=8[(1/2)x+3/4]
y=4x+6
I wish I could see your book.
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11/20/13
Trinity K.
thank you, I understand what I was doing wrong now.
the book I am using is here: http://www.bigideasmath.com/students/?level=9.00, Big Ideas Math: Grade 8 Florida (not Florida Core).
Thanks again. I have a test tomorrow and this should help.
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11/20/13
Inactive Tutor
Can you give me a page number?
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11/20/13
Trinity K.
page 97, problem #15
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11/21/13
Inactive Tutor
I am working on it.
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11/21/13
Inactive Tutor
Is that the correct page number?
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11/21/13
Trinity K.
yes, page 97, problem #15 is the one I was doing, the book is the 8th grade florida, it is blue and white with the kid playing soccer.
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11/21/13
Inactive Tutor
I cannot find it using the hyperlink you provided.
How did the test go?
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11/21/13
Trinity K.
11/20/13