If a+b +1 = 0, then the value of (a3+b3 +1 – 3ab) is ;

If $a+b+c=0 ; a^{3}+b^{3}+c^{3}-3 a b c$

$=(a+b+c) imesleft(a^{2}+b^{2}+c^{2}+a b+b c+c a ight)$

then $a^{3}+b^{3}+c^{3}-3 a b c=0$