Question

Answer 1

`10)P=(2x-3)(4x^2+6x+9)-(1+2x)(1-2x+4x^2)

    `P=8x^3-27-1-8x^3=-28`

  `->\bb A`

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`11)(x-1)^3-(x+3)(x^2-3x+9)+3(x^2-4)=2`

`<=>x^2-3x^2+3x-1-x^3-27+3x^2-12=2`

`<=>3x=42`

`<=>x=14`

    `->\bb A`

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`12)3x(x-y)-6y(y-x)`

`=3x(x-y)+6y(x-y)`

`=(x-y)(3x+6y)`      

`=3(x-y)(x+2y)`

             `->A`

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`13)-x^2-2x+8=-x^2-4x+2x+8=-x(x+4)+2(x+4)=(x+4)(-x+2)`

   `->\bb B`