mn giúp em 1 bài này:(

Đáp án:

Giải thích các bước giải:

 `a)`

`M=2x^2(1-3x+2x^2)`

`=2x^2-6x^3+4x^4`

`=4x^4-6x^3+2x^2`

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 `b)`

`N=(2x^2-3x+4)*((-1)/2x)`

`=((-1)/2x)*2x^2+((-1)/2x)*(-3x)+((-1)/2x)*4`

`=-x^3+3/2x^2-2x`

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 `c)`

`P=1/2xy(-x^8+2xy-4y^2)`

`1/2xy*(-x^8)+1/2xy*2xy-1/2xy*4y^2`

`=-1/2x^9y+x^2y^2-2xy^3`

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 `d)`

`1/2x^2y(2x^3-2/5xy^2-1)`

`=1/2x^2y*2x^3-1/2x^2y*2/5xy^2-1/2x^2y`

`=x^5y-1/5x^2y^3-1/2x^2y`