phân tích đa thức thành nhân tử a)`14(x-y)^2+21(y-x)` b)`7x^5(y-3)-49x^4(3-y)^3` c)`(x^2-9)^2-x^2(x-3)^2` d)`(4x^2-1)^2-9(2x-1)^2`

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phân tích đa thức thành nhân tử
a)`14(x-y)^2+21(y-x)`
b)`7x^5(y-3)-49x^4(3-y)^3`
c)`(x^2-9)^2-x^2(x-3)^2`
d)`(4x^2-1)^2-9(2x-1)^2`

0 thoughts on “phân tích đa thức thành nhân tử a)`14(x-y)^2+21(y-x)` b)`7x^5(y-3)-49x^4(3-y)^3` c)`(x^2-9)^2-x^2(x-3)^2` d)`(4x^2-1)^2-9(2x-1)^2`”

  2. a, 14(x – y)² + 21(y – x)

    = 14(y – x)² + 21(y – x)

    = (y – x)[14(y – x) + 21]

    = (y – x)(14y – 14x + 21)

    = (y – x) . 7(2y – 2x + 3)

    = 7(y – x)(2y – 2x + 3)

    b, 7$x^{5}$(y – 3) – 49$x^{4}$(3 – y)³

    = 7$x^{5}$(y – 3) + 49$x^{4}$(y – 3)³

    = 7$x^{4}$(y-3).[x + 7(y – 3)²]

    = 7$x^{4}$(y – 3).[x + 7(y² – 6x + 9)]

    = 7$x^{4}$(y – 3)(x + 7y² – 42x + 63)

    = 7$x^{4}$(y – 3)(7y² – 41x + 63)

    c, (x² – 9)² – x²(x – 3)²

    = (x – 3)²(x + 3)² – x²(x – 3)²

    = (x – 3)².[(x + 3)² – x²]

    = (x – 3)²(x² + 6x + 9 – x²)

    = (x – 3)²(6x + 9)

    = 3(x – 3)²(2x + 3)

    d, (4x² – 1)² – 9(2x – 1)²

    = (2x – 1)²(2x + 1)² – 9(2x – 1)²

    = (2x – 1)².[(2x + 1)² – 9]

    = (2x – 1)²(4x² + 4x + 1 – 9)

    = (2x – 1)²(4x² + 4x – 8)

    = 4(2x – 1)²(x² + x – 2)

    = 4(2x – 1)²(x² – x + 2x – 2)

    = 4(2x – 1)²(x – 1)(x + 2)

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