BÀi 2:
x=2009
=>x-1=2008
\(A=x^{2009}-2008x^{2008}-2008x^{2007}-\cdots-2008x+1\)
\(=x^{2009}-x^{2008}\left(x-1\right)-x^{2007}\left(x-1\right)-\cdots-x\left(x-1\right)+1\)
\(=x^{2009}-x^{2009}+x^{2008}-x^{2008}+x^{2007}-\cdots-x^2+x+1\)
=x+1
=2009+1
=2010
Bài 1:
\(M=x\left(x^{n-1}-y^{n-1}\right)+y^{n-1}\left(x-y\right)+\left(100-x^{n}+y^{n}\right)\)
\(=x^{n-1}\cdot x^1-xy^{n-1}+xy^{n-1}-y^{n-1}\cdot y+100-x^{n}+y^{n}\)
\(=x^{n}-y^{n}+100-x^{n}+y^{n}\)
=100
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