If the polynomial $P(x)={ x }^{ 9 }-{ x }^{ 6 }+{ x }^{ 3 }-1$
leaves $r(x)$ as remainder when divided by $d(x)={ x }^{ 2 }+x+1$, then,
evaluate $r(2015)$.

Inspiration: Preparatory Classes to the Technological Institute of Aeronautics (ITA - Brazil).

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