1. Tìm x a) (x-1)(x^2+x+1)-(2+x)(4-2x+x^2)=3x b) 8(x- 1/2)(x^2+1/2x+1/4)-x(1+8x^2)+2=0

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1. `a,(x-1)(x^2+x+1)-(2+x)(4-2x+x^2)=3x`

   `⇔x^3-1-8-x^3=3x`

   `⇔3x=-9`

   `⇔x=-3`

   `b,8(x-1/2)(x^2+1/2 x+1/4)-x(1+8x^2)+2=0`

   `⇔8(x^3-1/8)-x-8x^3+2=0`

   `⇔8x^3-1-x-8x^3+2=0`

   `⇔-x=-1`

   `⇔x=1`

   Trả lời