Question

Answer 1

a) \(\left(x+3\right)\left(x^2-3x+9\right)-\left(54+x^3\right)\)

\(=\left(x^3+3^3\right)-54-x^3\)

\(=x^3+27-54-x^3\)

\(=-27\)

Answer 2

a: \(\left(x+3\right)\left(x^2-3x+9\right)-\left(x^3+54\right)\)

\(=x^3+27-x^3-54\)

=-27

b: \(\left(2x+y\right)\left(4x^2-2xy+y^2\right)-\left(2x-y\right)\left(4x^2+2xy+y^2\right)\)

\(=8x^3+y^3-8x^3+y^3\)

\(=2y^3\)