Bài 1:
`a)`
`(3x+2y)^3`
`=(3x)^3+3.(3x)^{2}.2y+3.3x.(2y)^2+(2y)^3`
`=27x^3+3.9x^{2}.2y+9x.4y^2+8y^3`
`=27x^3+54x^2y+36xy^2+8y^3`
`b)`
`(101)^3`
`=(100+1)^3`
`=100^3+3.100^{2}.1+3.100.1+1`
`=1``000``000``+3.10000+300+1`
`=1``000``000``+30000+300+1`
`=1030301`
Bài 2:
`a)`
`27x^3+27x^2+9x+1`
`=(3x)^3+3.9x^2+3.3x+1`
`=(3x)^3+3.(3x)^2+3.3x+1`
`=(3x+1)^3`
`b)`
`x^3+3\sqrt2x^2y+6xy^2+2\sqrt2y^3`
`=x^3+3.x^{2}.\sqrt2y+3.x.2y^2+(\sqrt2y)^3`
`=x^3+3.x^{2}.\sqrt2y+3.x.(\sqrt2y)^2+(\sqrt2y)^3`
`=(x+\sqrt2y)^3`
