f)
8$x^{3}$ + 27 $y^{3}$
= ( 8x + 27y ) . (8$x^{2}$ - 8x . 27y + 27$x^{2}$ )
= ( 8x + 27y ) . (8$x^{2}$ - 216xy + 27$x^{2}$ )
= ( 8x + 27y ) . (35$x^{2}$ - 216xy)
g)
4$x^{2}$ + 4x + 1
= $(2x)^{2}$ + 2.2x1 + 1$^{2}$
= (2x + 1)$^{2}$
= (2x + 1) . (2x + 1)
h)
9$x^{2}$ - 6x - 24
= 3(3$x^{2}$ −2x −8)
= 3(3$x^{2}$ + 4x - 6x −8)
= 3 .[ x( 3x + 4) - 2(3x + 4)]
= 3 . ( 3 x + 4 ) . ( x - 2 )
Chúc bạn học tốt.
