`a)` `(2x-1)(3x+2)(3-x)`
`=(6x^2+4x-3x-2)(3-x)`
`=(6x^2+x-2)(3-x)`
`=18x^2-6x^3+3x-x^2-6+2x`
`=17x^2-6x^3+5x-6`
`=-6x^3+17x^2+5x-6`
`b)` `(x-2y)^2`
`=x^2-2x.2y+(2y)^2`
`=x^2-4xy+4y^2`
`c)` `(2x^2+3)^2`
`=(2x^2)^2+2.2x^2.3+3^2`
`=4x^4+12x^2+9`
`d)` `(x-2)(x^2+2x+4)`
`=x^3-2^3`
`=x^3-8`
`e)` `(2x-1)^3`
`=(2x)^3-3.(2x)^2.1+3.2x.1^2-1^3`
`=8x^3-3.4x^2.1+3.2x.1-1`
`=8x^3-12x^2+6x-1`