Đáp án:
`a)(3x-1)^2`
`= 9x^2 - 6x + 1`
`b)25x^2+10x+1`
`= ( 5x + 1)^2`
`c)(x+1/3)^3`
`= x^3 + x^2 + 1/3 x + 1/27`
`d) 8x^6 - 27`
`= ( 2x^2)^3 - 3^3`
`= ( 2x^2 - 3)( 4x^4 + 6x^2 +9)`
`e)5x^2-9`
`= (\sqrt{ 5} x - 3)( \sqrt{ 5} x + 3)`
`f)x^3+12x+6x^2+8`
`= ( x + 2)^3`