SOLUTION: how the equation 5(-1+5y)/(-4)-7y = 8 arrive at this one 3y = -27?

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Question 558843: how the equation 5(-1+5y)/(-4)-7y = 8 arrive at this one 3y = -27?
Answer by bucky(2189) About Me  (Show Source):
You can put this solution on YOUR website!
Your problem is:
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%28%285%2A%28-1%2B5y%29%29%2F%28-4%29%29-7y+=+8
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and it likely has an error with one of the signs because solving this problem does not lead to 3y = -27.
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Here's my work:
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You can eliminate the denominator on the left side by multiplying both sides of this equation (all terms) by -4.
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When you do that multiplication the problem becomes:
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%28%28-4%29%2A5%2A%28-1%2B5y%29%29%2F%28%28-4%29%29-7y%2A%28-4%29+=+8%2A%28-4%29
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On the left side, cancel the denominator with the common factor in the numerator as shown:
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and you are left with:
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5%2A%28-1%2B5y%29-7y%2A%28-4%29=+8%2A%28-4%29
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On the left side, do the distributed multiplication by multiplying the constant 5 times each of the terms in the parentheses to get:
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-5+%2B+25y+-7y%2A%28-4%29=+8%2A%28-4%29
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On the left side multiply the -7y times the -4 to get +28y and on the right side multiply the 8 times the -4 to get -32. This results in the equation becoming:
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-5+%2B+25y+%2B28y=+-32
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get rid of the -5 on the left side by adding +5 to both sides as follows:
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%2B5+-+5+%2B+25y+=+%2B5+-+32+
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On the left side the +5 and -5 cancel out and on the right side the +5 and the -32 combine to give -27. As a result you are left with:
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25y+%2B+28y+=+-32
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Combine the two terms on the left side and you get:
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53y+=+-32
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This obviously is not the answer you were looking forward. I expect that your problem has a sign error because if you had arrived at:
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-25y+%2B+28y+=+-32
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the result would be:
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3y+=+-32
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and that would be what you were expecting.
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Maybe your original problem should have had a negative sign in the factor:
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%28-1%2B5y%29
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so that it was -1+-5yinstead.
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I hope this helps you to find where the error is. If it doesn't please post the problem again and maybe another tutor can find what is wrong here.
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