x³ - 3x² + 4x - 12
Notice that the ratio of the first two coefficients (1:-3) is the same as the ratio of the last two (4:-12 = 1:-3). Whenever this happens (or when the ratio of the 1st and 3rd is the same as the ratio of the 2nd and 4th), you will have a common factor.
Factor x² out of the first two, and 4 out of the last two:
x²(x - 3) + 4(x - 3)
Now you can factor (x + 3) out of both:
(x - 3)(x² + 4)
Since x² + 4 is not factorable (over the real numbers), that's as far as you can go.
If you're looking for complex roots too, then x² + 4 factors to x + 2i and x - 2i:
(x + 3)(x - 2i)(x + 2i)
2007-01-03 13:26:19
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answer #1
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answered by Jim Burnell 6
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x^3-3x^2+4x-12 1 factor is x-3
x^2+4
(x-3)\x^3 - 3 x^2 + 4 x - 12
- ( x^3 - 3 x^2)
4 x - 12
4x -12
0
x^3-3x^2+4x-12=(x-3)(x^2+4) x^2+4 has no real factors
(x-3)(x+2i)(x-2i)
2007-01-03 22:25:00
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answer #2
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answered by yupchagee 7
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x^3-3x^2+4x-12
Group the first two terms and the last two terms together.
x^3-3x^2 + 4x-12
Factor an x^2 out of the first group and a 4 out of the second group.
x^2(x-3) + 4(x-3)
Factor (x-3) out of both terms and your answer is:
(x-3)(x^2+4)
2007-01-03 21:29:01
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answer #3
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answered by vinnistelrooy 2
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Looks like factor by grouping
x^2(x-3)+4(x-3)=(x^2+4)(x-3)
2007-01-03 21:26:38
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answer #4
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answered by christopher_az 2
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x^3 - 3x^2 + 4x - 12
(x^2 + 4)(x - 3)
2007-01-03 21:28:28
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answer #5
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answered by Johnny Handsome 2
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x^3-3x^2+4x-12 = (x-3)(x^2 + 4)
Now if you're not restricted to real factors..
x^3-3x^2+4x-12 = (x-3)(x+2i)(x-2i)
2007-01-03 21:32:44
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answer #6
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answered by The Alchemist 2
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x^3-3x^2+4x-12
=x^2(x-3) +4(x-3)
=(x^2+4)(x-3)
2007-01-03 21:29:38
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answer #7
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answered by ironduke8159 7
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x^2(x-3)+4(x-3)
(x^2+4)(x-3)
2007-01-03 21:53:25
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answer #8
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answered by Anonymous
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(x-3)(x^2+4)
Unfortunately, (x^2+4) can not be factored (using real numbers). It does, however, factor into (x+2i)(x-2i), using i (the square root of -1).
So the roots of the equation are 3 (the only real root) and 2i and -2i.
2007-01-03 21:33:30
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answer #9
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answered by actuator 5
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x^3-3x^2+4x-12
(x^3-3x^2)+(4x-12)
x^2(x-3)+4(x-3)
(x^2+4)(x-3)
(x-2i)(x+2i)(x-3)
x= 2i, -2i and 3
2007-01-03 21:29:05
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answer #10
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answered by 7
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