2X^2 + 9X-35 = (x+7)(2x-5)
8X^2 + 2X- 15 = (2x+3)(4x-5)
2007-08-28 15:31:34
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answer #1
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answered by Kemmy 6
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2x^2 + 9x - 35
[Multiply (2)(-35) = -70. Find two factors of 70 which differ by 9. 1&70, 2&35, 5&14, 7&10. Use 5 & 14.]
2x^2 + 14x - 5x - 35 [re-write 9x as the difference of them]
2x (x + 7) - 5 (x + 7) [take the common factor out of each pair]
(x + 7) (2x - 5) [take the common (x + 7) out of each term]
8x^2 + 2x - 15
[ (8)(-15) = -120. Factors which differ by 2: 1&120, 2&60, 3&40, 4&30, 5&24, 6&20, 8&15, 10&12. See what you can do to finish this one.]
2007-08-28 22:42:35
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answer #2
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answered by JM 4
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I assume you want these factored.
In the first, you will have possible combos of 1 and 2 for the x-square term and +/-1, +/-35, +/-5 and -/+ 7 for the -35 term. Also, the cross terms have to wind up with +9. Some thought gives you
(2x - 5)(x + 7)
Same deal here/ your combos are 1,8,2 and 4 for the "8" and +/-1,-/+15,+/-3,-/+5 for the "-15", and cross terms have to come out to +2.
(4x-5)(2x+3)
There is a more organized way to do this, but boiled down to its bare essentials, it is as much trial and error as this is.
2007-08-28 22:38:02
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answer #3
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answered by cattbarf 7
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1)
2x^2 + 9x - 35
2x^2 + 14x - 5x - 35
2x(x + 7) - 5(x + 7)
(2x - 5)(x + 7)
2)
8x^2 + 2x - 15
8x^2 + 12x - 10x - 15
4x(2x + 3) - 5(2x + 3)
(4x - 5)(2x + 3)
2007-08-28 22:44:58
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answer #4
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answered by mohanrao d 7
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Nerd. Jk. I dont know.
2007-08-28 22:29:56
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answer #5
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answered by Anonymous
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what the question
2007-08-28 22:34:03
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answer #6
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answered by Di 2
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