7x(x-y)+2`(x-y)^2` b)`9x^2` + 6x – 35 c)`x^2`-`y^2`+6y-9 d`49x^3` – `14x^2y` + `xy^2` e) `3x^2` – 6xy + `3y^2 -12z^2` f) ` 3x

1 bình luận về “7x(x-y)+2`(x-y)^2` b)`9x^2` + 6x – 35 c)`x^2`-`y^2`+6y-9 d`49x^3` – `14x^2y` + `xy^2` e) `3x^2` – 6xy + `3y^2 -12z^2` f) ` 3x”

1. 1)

   7x.(x-y)+2.(x-y)^2

   =(x-y).[7+2.(x-y)]

   =(x-y).(7+2x-2y)

   2)

   9x^2+6x-35

   =(9x^2+6x+1)-36

   =[(3x)^2+2.3x.1+1^2]-36

   =(3x+1)^2-6^2

   =(3x+1-6).(3x+1+6)

   =(3x-5).(3x+7)

   3)

   x^2-y^2+6y-9

   =x^2-(y^2-6y+9)

   =x^2-(y^2-2.y.3+3^2)

   =x^2-(y-3)^2

   =(x-y+3).(x+y-3)

   4)

   49x^3-14x^2y+xy^2

   =x.(49x^2-14xy+y^2)

   =x.[(7x)^2-2.7x.y+y^2]

   =x.(7x-y)^2

   5)

   3x^2-6xy+3y^2-12z^2

   =3.(x^2-2xy+y^2-4z^2)

   =3.[(x^2-2xy+y^2)-4z^2]

   =4.[(x-y)^2-(2z)^2]

   =4.(x-y-2z).(x-y+2z)

   6)

   3x^2-3y^2+12x-12y

   =3.(x^2-y^2)+12.(x-y)

   =3.(x-y).(x+y)+12.(x-y)

   =(x-y).[3.(x+y)+12]

   =(x-y).[3.(x+y)+3.4]

   =(x-y).3.(x+y+4)

   g)

   6x^2-3x+10x-5

   =(6x^2-3x)+(10x-5)

   =3x.(2x-1)+5.(2x-1)

   =(3x+5).(2x-1) 

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