`d) (2x-1)(4x^2 + 2x + 1) - 4x(2x^2 - 3)`
`= (2x-1)[(2x)^2 + 2x.1 + 1^2] - 4x.2x^2 -4x.-3`
`= (2x)^3 - 1^3 - 8x^3 + 12x`
`= 8x^3 - 1 - 8x^3 + 12x`
`= (8x^3 - 8x^3) + 12x -1`
`= 12x -1`
`e) (x+2)(x^2 - 2x + 4)-(x^3 - 2)`
`= (x+2)(x^2 - x.2 + 2^2)-(x^3 - 2)`
`= x^3 + 2^3 - x^3 + 2`
`= (x^3 - x^3) + 8 +2`
`= 0 + 8 +2`
`= 10`
`f) (a+2)(a-2)(a^2 + 2a + 4)(a^2 - 2a + 4)`
`= [(a+2)(a^2 + a.2 + 2^2)][(a-2)(a^2 - a.2 + 2^2)]`
`= (a^3 + 2^3)(a^3 - 2^3)`
`= (a^3)^2 - (2^3)^2`
`= a^(3.2) - 2^(3.2)`
`= a^6 - 2^6`
`= a^6 - 64`
