## Division of polynomials: answers not matching

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.
myself5
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### Division of polynomials: answers not matching

On Elementary Algebra page 243 problem 72, it says to divide 9x^2 – 9x – 28 by 3x+4. The answer they gave was 3x-7 with no remainder. My answer was 3x+ 21 with a remainder of 84 - 112. This is what I did:

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``` 3x + 21 ------------- 3x+4) 9x^2 – 9x – 28 -9x^2 – 12x ------------- - 21x – 28 - 63x + 84 ------------- 84 – 112```

This is at least the third time I have had this problem in the last page and a half. Can anyone see where I went wrong?

stapel_eliz
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...divide 9x^2 – 9x – 28 by 3x+4.
I'm not sure what you're doing in your second multiplication and subtraction...?

You did the first multiplication and subtraction, and ended up with -21x - 28 as your new dividend. Why did you multiply the 3x by -21 instead of by -7...?

Eliz.

myself5
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### Re:

You did the first multiplication and subtraction, and ended up with -21x - 28 as your new dividend. Why did you multiply the 3x by -21 instead of by -7...?
Yeah, it appears I was using the wrong number. I think I have it figured out now. Thanks so much for your help!