Question

(x - 4)(x² + 4x + 16) - (x³ + 128)

Answer 1

\(=\left(x^3-64\right)-x^3-128\\ =x^2-64-x^3-128\\ =-192\)

Answer 2

\(\left(x-4\right)\left(x^2+4x+16\right)-\left(x^3+128\right)\)

\(=x^3-4^3-\left(x^3+128\right)\)

\(=x^3-64-x^3-128\)

\(=-192\)

HĐT: \(\left(a-b\right)\left(a^2-ab+b^2\right)=a^3-b^3\)