Đáp án+Giải thích các bước giải:

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 `1)(x+3)^{3}=x^{3}+3.x^{2}.3+3.x.3^{2}+3^{3}`

`=x^{3}+9x^{2}+27x+27`

`2)(3x+2)^{3}=(3x)^{3}+3.(3x)^{2}.2+3.3x.2^{2}+2^{3}`

`=27x^{3}+54x^{2}+36x+8`

`3)(x-3)^{3}=x^{3}-3.x^{2}.3+3.x.3^{2}-3^{3}`

`=x^{3}-9x^{2}+27x-27`

`4)(3x-1)^{3}=(3x)^{3}-3.(3x)^{2}.1+3.3x.1^{2}-1^{3}`

`=27x^{3}-27x^{2}+9x-1`

`5)1+8x^{3}=1^{3}+(2x)^{3}`

`=(1+2x).[1-1.2x+(2x)^{2}]`

`=(1+2x).(1-2x+4x^{2})`

`6)x^{3}+8y^{3}=x^{3}+(2y)^{3}`

`=(x+2y).[x^{2}-x.2y+(2y)^{2}]`

`=(x+2y).(x^{2}-2xy+4y^{2})`

`7)1-8x^{3}`

`=1^{3}-(2x)^{3}`

`=(1-2x).[1^{2}+1.2x+(2x)^{2}]`

`=(1-2x).(1+2x+4x^{2})`

`8)27x^{3}-1=(3x)^{3}-1^{3}`

`=(3x-1).[(3x)^{2}+3x.1+1^{2}]`

`=(3x-1).(9x^{2}+3x+1)`