`2)(2x+y²)^3`
`=(2x)³+3.(2x)².y²+3.2x.(y²)^2+(y²)^3`
`=8x³+12x²y²+6xy^4+y^6`
`3)(1/2x²+1/3y)³`
`=(1/2x²)^3+3.(1/2x²)^2. 1/3y+3. 1/2x² .(1/3y)^2+(1/3y)^3`
`=1/8x^6+1/4x^4y+1/6x^2y^2+1/27y^3`
`4)(3x^2-2y)^3`
`=(3x^2)^3-3.(3x^2)^2 .2y+3.3x^2.(2y)^2-(2y)^3`
`=27x^6-54x^4y+36x^2y^2-8y^3`
`5)(2/3x^2-1/2y)^3`
`=(2/3x^2)^3-3.(2/3x^2)^2. 1/2y+3. 2/3x^2 .(1/2y)^2+(1/2y)^3`
`=8/27x^6-2/3x^4y+1/2x^2y^2+1/8y^3`
`6)(2x+1/2)^3`
`=(2x)^3+3.(2x)^2. 1/2+3.2x. (1/2)^2+(1/2)^3`
`=8x^3+6x^2+3/2x+1/8`
`7)(x-3)³`
`=x³-3.x².3+3.x.3²-3³`
`=x³-9x²+27x-27`
`13)(x²-1/3)(x^4+1/3x²+1/9)`
`=(x²-1/3)[(x²)^2+x². 1/3+(1/3)^2]`
`=(x²)^3-(1/3)^3`
`=x^6-1/27`
`14)(1/3x-2y)(1/9x^2-2/3xy+4y^2)`
`=(1/3x-2y)[(1/3x)^2-1/3x .2y+(2y)^2]`
`=(1/3x)^3-(2y)^3`
`=1/27x^3-8y³`
