Đáp án:
a) (x + 2)(x² - 2x + 4)
= (x + 2)(x² - x.2 + 2²)
= x³ + 2³
= x³ + 8
b) (x - 1)(x² - x + 1)
= (x - 1)( x² + x.1 + 1²)
= x³ - 1³
= x³ - 1
c) (x + 3)(x² - 3x + 9)
= (x + 3)(x² - x.3 + 3²)
= x³ + 3³
= x³ + 27
d) (3x - 4)(9x² + 12x + 16)
= (3x - 4)((3x)²+ 3x.4 + 4²)
= (3x)³ - 4³
= 27x³ - 64
e) (2x + 3y)( 4x² - 6xy + 9y²)
= (2x + 3y)((2x)² - 2x.3y + (3y)²)
=(2x)³ + (3y)³
= 8x³ + 27y³
