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eyust707
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simplify?
mike12
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how
Callisto
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Do you need to factorize it or expand it?
mike12
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factorize
Callisto
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Use \(a^3 - b^3 = (a-b)(a^2+ab+b^2)\)
Callisto
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FYI, 64=4^3
abb0t
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I believe the answer is:
\[6x^3+384\]
mike12
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i started off with 6x^3 +384
joyap03
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distribution :)
sir abbot is right
Callisto
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Factorize.. not expand..
Callisto
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And if you started from 6x^3 +384, you shouldn't get 6(x^3-64)...
mike12
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i got 6(x^3-64)
Callisto
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What is the original question?
mike12
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factor 6x^3-384
Silenthill
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= 6x^3-384 or 6(x-4)(x^2+4x+16)
Callisto
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@mike12 Then you did right.
6x^3-384
= 6(x^3 - 64)
Note that 64 can be written as 4^3, so you get
= 6(x^3 - 4^3)
Next apply the identity \(a^3-b^3 = (a-b)(a^2+ab+b^2)\) to factorize x^3 - 4^3. Can you do it?
mike12
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ill try
mike12
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give me a second
Callisto
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Take your time :)
mike12
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lol yeah im pretty lost
Callisto
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Where?
mike12
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applying the identity
Callisto
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Have you learnt that identity yet?
mike12
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yeah but actually trying to sub it in...having troubles
Callisto
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What troubles?
Can you show your work?
mike12
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honestly just plugging in the equation... i dont know what to plug in or where
Callisto
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Compare
\(x^3 - 4^3 \) and
\(a^3-b^3\)
Can you identify what is a and b?
mike12
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yeah
Callisto
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What are they then?
Callisto
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@mike12 What are a and b...???