a. 5x ²(4x ²-2x+1) b. (3x ³-2)(-4x ²-x+3) c. (x^4-3x ³-6x ²+21x)-1

0 bình luận về “a. 5x ²(4x ²-2x+1) b. (3x ³-2)(-4x ²-x+3) c. (x^4-3x ³-6x ²+21x)-1”

1. `a. 5x ²(4x ²-2x+1)`

   `<=>20x^4-10x^3+5x^2`

   `b. (3x ³-2)(-4x ²-x+3)`

   `<=>3x^3(-4x ²-x+3)-2(-4x ²-x+3)`

   `<=>-12x^5-3x^4+9x^3+8x^2+2x-6`

   `c. (x^4-3x ³-6x ²+21x)-1`

   `<=>-x^4+3x^3+6x^2-21x`

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2. `a)5x^2(4x^2-2x+1)`

   `=5x^2.4x^2+5x^2.(-2x)+5x^2.1`

   `=20x^4-10x^3+5x^2.`

   `b)(3x^3-2)(-4x^2-x+3)`

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

   `=-12x^5-3x^4+9x^3+8x^2+2x-6`

   `c)`Nếu là `-1:`

   (x^4-3x^3-6x^2+21x)-1`

   `=x^4-3x^3-6x^2+21x-1`

   Nếu là `.(-1):`

   `(x^4-3x^3-6x^2+21x).-1`

   `=x^4+3x^3+6x^2-21x.`

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