(x+1)(x2-x+1)-(x3+27)
=(x3+1)-(x3+27)
=x3+1-x3-27
=-26
\(\left(x+1\right)\left(x^2-x+1\right)-\left(x^3+27\right)\)
\(=x^3+1^3-x^3-27=-26\)
\(\left(x+1\right)\left(x^2-x+1\right)-\left(x^3+27\right)\)
\(=\left(x^3+1\right)-\left(x^3-27\right)\)
\(=x^2+1-x^2-27\)
\(=-26\)