Phân tích đa thức thành nhân tử `x^4-3x^3-x+3` $x^2y^2\left(y-x\right)+y^2z^2\left(x-y\right)-z^2x^2\left(z-x\right)$ 02/11/2021 Bởi aikhanh Phân tích đa thức thành nhân tử `x^4-3x^3-x+3` $x^2y^2\left(y-x\right)+y^2z^2\left(x-y\right)-z^2x^2\left(z-x\right)$
Đáp án: Giải thích các bước giải: `a)` `x^4-3x^3-x+3` `=(x^4-3x^3)-(x-3)` `=x^3(x-3)-(x-3)` `=(x-3)(x^3-1)=(x-3)(x-1)(x^2+x+1)` `b)` `=x^2y^2(y-x)-y^2z^2(y-x)-z^2x^2(z-x)` `=(y-x)(x^2y^2-y^2z^2)-z^2x^2(z-x)` `=y^2(y-x)(x^2-z^2)-z^2x^2(z-x)` `=y^2(y-x)(x-z)(x+z)+z^2x^2(x-z)` `=(x-z)[y^2(y-x)(x+z)+z^2x^2]` Bình luận
Bài làm : `x^4−3x^3−x+3` `=x^4−x^3−2x^3+2x^2−2x^2+2x−3x+3` `=x^3(x−1)−2x^2(x−1)−2x(x−1)−3(x−1)` `=(x^3−2x^2−2x−3)(x−1)` `=(x^3+x^2+x−3x^2−3x−3)(x−1)` `=(x^2+x+1)(x−3)(x−1)` — `x^2y^2(y−x)+y^2z^2(x−y)−z^2x^2(z−x)` `=−x^2y^2(x−y)+y^2z^2(x−y)−z^2x^2(z−x)` `=(y^2z^2−x^2y^2)(x−y)−z^2x^2(z−x)` `=y^2(z^2−x^2)(x−y)−z^2x^2(z−x)` `=[y^2(z+x)(x−y)−z^2x^2](z−x)` Bình luận
Đáp án:
Giải thích các bước giải:
`a)`
`x^4-3x^3-x+3`
`=(x^4-3x^3)-(x-3)`
`=x^3(x-3)-(x-3)`
`=(x-3)(x^3-1)=(x-3)(x-1)(x^2+x+1)`
`b)`
`=x^2y^2(y-x)-y^2z^2(y-x)-z^2x^2(z-x)`
`=(y-x)(x^2y^2-y^2z^2)-z^2x^2(z-x)`
`=y^2(y-x)(x^2-z^2)-z^2x^2(z-x)`
`=y^2(y-x)(x-z)(x+z)+z^2x^2(x-z)`
`=(x-z)[y^2(y-x)(x+z)+z^2x^2]`
Bài làm :
`x^4−3x^3−x+3`
`=x^4−x^3−2x^3+2x^2−2x^2+2x−3x+3`
`=x^3(x−1)−2x^2(x−1)−2x(x−1)−3(x−1)`
`=(x^3−2x^2−2x−3)(x−1)`
`=(x^3+x^2+x−3x^2−3x−3)(x−1)`
`=(x^2+x+1)(x−3)(x−1)`
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`x^2y^2(y−x)+y^2z^2(x−y)−z^2x^2(z−x)`
`=−x^2y^2(x−y)+y^2z^2(x−y)−z^2x^2(z−x)`
`=(y^2z^2−x^2y^2)(x−y)−z^2x^2(z−x)`
`=y^2(z^2−x^2)(x−y)−z^2x^2(z−x)`
`=[y^2(z+x)(x−y)−z^2x^2](z−x)`