Mathematics
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OpenStudy (anonymous):
What is the sum of the coefficients of
( [3x - 3x^2 +1]^744 ) x ( [- 3x + 3x^2 +1]^745 ) ??
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OpenStudy (anonymous):
i bet we can do this, i need paper
OpenStudy (anonymous):
Good problem.
OpenStudy (anonymous):
Thanks I Know Its Hard
OpenStudy (anonymous):
hmm i was thinking along the lines of
\[(1+a)(1-a)=1-a^2\] with
\[a=x^2-3x\] but that did't get me too far yet
OpenStudy (anonymous):
oh
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OpenStudy (anonymous):
oh hold the phone. sum of coefficients is what you get when x = 1
OpenStudy (anonymous):
wow your smart :)
OpenStudy (anonymous):
so we can write as
\[
\[1-9 (x^2-x)^2\]
OpenStudy (anonymous):
:)
OpenStudy (anonymous):
that is
\[(3x - 3x^2 +1 ) \times(- 3x + 3x^2 +1)=1-9(x^2-x)^2\] right?
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OpenStudy (anonymous):
then raise to the power of whatever, say 755 and get
\[(1-9(x^2-x)^2)^{755}\]
OpenStudy (anonymous):
how am i doing so far?
OpenStudy (anonymous):
wow :O your smart thanks
OpenStudy (anonymous):
:)
OpenStudy (anonymous):
replace x by 1, get 1
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OpenStudy (anonymous):
so the answer is 1?
OpenStudy (anonymous):
oh wait you have another term but you can cope with that
OpenStudy (anonymous):
alright
OpenStudy (anonymous):
\[(1-9(x^2-x)^2)^{744}(- 3x + 3x^2 +1)\] is what you have
OpenStudy (anonymous):
replace x by 1, first term gives 1, second one gives ... 1 as well
so i guess the answer is 1
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OpenStudy (anonymous):
probably was an easier way to do it. repost and i bet you will get one
OpenStudy (anonymous):
thanks :)