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[tex]\bf 8^{n}+8^{n+1}=18 \cdot 2^{2003}[/tex]
[tex]\bf 8^{n} \cdot(8^{n-n}+8^{n+1-n}) =9\cdot 2 \cdot 2^{2003}[/tex]
[tex]\bf 8^{n} \cdot(8^{0}+8^{1}) =9\cdot 2^{2003 +1}[/tex]
[tex]\bf 8^{n} \cdot(1+8) =9\cdot 2^{2004}[/tex]
[tex]\bf 8^{n} \cdot 9 =9\cdot 2^{2004}\:\:\:|:9\:\:\text{(\it impartim toata relatia cu 9)}[/tex]
[tex]\bf 8^{n} = 2^{2004}[/tex]
[tex]\bf (2^{3})^{n} = 2^{2004}[/tex]
[tex]\bf 2^{3\cdot n} = 2^{2004}[/tex]
[tex]\bf 2^{3n} = 2^{2004}[/tex]
[tex]\bf 3n = 2004\:\:\:|:3\:\:\text{(\it impartim toata relatia cu 3)}[/tex]
[tex]\boxed{\bf n = 668}[/tex]
==pav38==