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Algebra Difficulty 3.7 AMC 10/12 Find the answer Italy

The polynomial p(x)p(x) has the following property: for every triple of integers a,b,ca, b, c such that a+b+c=2022a+b+c=2022 we have p(a)+p(b)+p(c)=p(674)p(a)+p(b)+p(c)=p(674). It is also known that p(0)=2696p(0)=-2696. What is p(2022)p(2022)?

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Solution

Solution:

The answer is (C)\mathbf{(C)}. Substituting a=b=c=674a=b=c=674 (integers that indeed satisfy a+b+c=2022a+b+c=2022) we obtain 3p(674)=p(674)3p(674)=p(674), that is p(674)=0p(674)=0. Substituting then a=b=0a=b=0 and c=2022c=2022 we obtain
2p(0)+p(2022)=p(674)=0p(2022)=2p(0)=5392. 2p(0)+p(2022)=p(674)=0 \Rightarrow p(2022)=-2p(0)=5392.

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Source: MathNet, licensed CC-BY-4.0. Statement translated into English from it; metadata (topic, difficulty) added by this project.